Stimulation apparatus

ABSTRACT

A medical apparatus for a patient comprises an external system and an implantable system. The external system is configured to transmit one or more transmission signals, each transmission signal comprising at least power or data. The implantable system is configured to receive the one or more transmission signals from the external system, and to deliver stimulation energy to the patient. Methods of delivering stimulation energy are also provided.

CROSS-REFERENCE

This application is a continuation of PCT Application No.PCT/US20/40766, filed Jul. 2, 2020; which claims priority to U.S.Provisional Application No. 62/869,985, filed Jul. 2, 2019; and U.S.Provisional Application No. 62/894,077, filed Aug. 30, 2019; thecontents of which are incorporated herein by reference in their entiretyfor all purposes.

RELATED APPLICATIONS

This application is related to: U.S. patent application Ser. No.14/975,358, titled “Method and Apparatus for Minimally InvasiveImplantable Modulators”, filed Dec. 18, 2015 [Docket nos. 47476.703.301;NAL-005-US]; U.S. patent application Ser. No. 15/664,231, titled“Medical Apparatus Including an Implantable System and an ExternalSystem”, filed Jul. 31, 2017 [Docket nos. 47476-706.301; NAL-011-US];U.S. patent application Ser. No. 15/916,023, titled “Apparatus forPeripheral or Spinal Stimulation”, filed Mar. 8, 2018 [Docket nos.47476-707.301; NAL-012-US]; U.S. patent application Ser. No. 16/104,829,titled “Apparatus with Enhanced Stimulation Waveforms”, filed Aug. 17,2018 [Docket nos. 47476-708.301; NAL-014-US]; U.S. patent applicationSer. No. 16/111,868, titled “Devices and Methods for PositioningExternal Devices in Relation to Implanted Devices”, filed Aug. 24, 2018[Docket nos. 47476-709.301; NAL-016-US]; U.S. patent application Ser.No. 16/120,139, titled “Methods and Systems for Insertion and Fixationof Implantable Devices”, filed Aug. 31, 2018 [Docket nos. 47476-710.301;NAL-013-US]; U.S. patent application Ser. No. 16/222,959, titled“Methods and Systems for Treating Pelvic Disorders and Pain Conditions”,filed Dec. 17, 2018 [Docket nos. 47476-711.301; NAL-017-US]; U.S. patentapplication Ser. No. 16/266,822, titled “Method and Apparatus forVersatile Minimally Invasive Neuromodulators”, filed Feb. 4, 2019[Docket nos. 47476-704.302; NAL-007-US-CON1]; U.S. patent applicationSer. No. 16/408,989, titled “Method and Apparatus for NeuromodulationTreatments of Pain and Other Conditions”, filed May 10, 2019 [Docketnos. 47476.705.302; NAL-008-US-CON1]; U.S. patent application Ser. No.16/453,917, titled “Stimulation Apparatus”, filed Jun. 26, 2019 [Docketnos. 47476-712.301; NAL-015-US]; U.S. patent application Ser. No.16/505,425, titled “Wireless Implantable Sensing Devices”, filed Jul. 8,2019 [Docket nos. 10220-728.300; NAL-006-US-CON1]; U.S. patentapplication Ser. No. 16/539,977, titled “Apparatus with SequentiallyImplanted Stimulators”, filed Aug. 13, 2019 [Docket nos. 47476-713.301;NAL-019-US]; U.S. patent application Ser. No. 16/672,921, titled“Stimulation Apparatus”, filed Nov. 4, 2019 [Docket nos. 47476-714.301;NAL-020-US]; U.S. Provisional Application Ser. No. 62/910,685, titled“Stimulation Apparatus”, filed Oct. 4, 2019 [Docket nos. 47476-715.103;NAL-021-PR3]; U.S. Provisional Application Ser. No. 62/933,184, titled“Stimulation Apparatus”, filed Nov. 8, 2019 [Docket nos. 47476-715.104;NAL-021-PR4]; U.S. Provisional Application Ser. No. 62/952,717, titled“System with Implanted Conduit Tracking”, filed Dec. 23, 2019 [Docketnos. 47476-716.101; NAL-022-PR1]; U.S. Provisional Application Ser. No.62/977,901, titled “Stimulation Apparatus”, filed Feb. 18, 2020 [Docketnos. 47476-715.105; NAL-021-PR5]; U.S. Provisional Application Ser. No.62/988,281, titled “Stimulation Apparatus”, filed Mar. 11, 2020 [Docketnos. 47476-714.301; NAL-021-PR6]; and U.S. Provisional Application Ser.No. 63/042,293, titled “Systems with Implanted Conduit Tracking”, filedJun. 22, 2020 [Docket nos. 47476-717.101; NAL-023-PR1]; the contents ofeach of which is incorporated herein by reference in its entirety forall purposes.

BACKGROUND OF THE INVENTION Field of the Invention

The present invention relates generally to medical apparatus for apatient, and in particular, apparatus that deliver enhanced stimulationto effectively deliver a therapy while avoiding undesired effects.

Background

Implantable devices that treat a patient and/or record patient data areknown. For example, implants that deliver energy such as electricalenergy, or deliver agents such as pharmaceutical agents are commerciallyavailable. Implantable electrical stimulators can be used to pace ordefibrillate the heart, as well as modulate nerve tissue (e.g. to treatpain). Most implants are relatively large devices with batteries andlong conduits, such as implantable leads configured to deliverelectrical energy or implantable tubes (i.e. catheters) to deliver anagent. These implants require a fairly invasive implantation procedure,and periodic battery replacement, which requires additional surgery. Thelarge sizes of these devices and their high costs have prevented theiruse in a variety of applications.

Nerve stimulation treatments have shown increasing promise recently,showing potential in the treatment of many chronic diseases includingdrug-resistant hypertension, motility disorders in the intestinalsystem, metabolic disorders arising from diabetes and obesity, and bothchronic and acute pain conditions among others. Many of theseimplantable device configurations have not been developed effectivelybecause of the lack of miniaturization and power efficiency, in additionto other limitations.

There is a need for apparatus, systems, devices and methods that provideone or more implantable devices and are designed to provide enhancedtreatment of pain and other enhanced benefits.

SUMMARY

According to an aspect of the present inventive concepts, a medicalapparatus for a patient comprises: an external system and an implantablesystem. The external system is configured to transmit one or moretransmission signals, each transmission signal comprising at least poweror data. The implantable system is configured to receive the one or moretransmission signals from the external system. The external systemcomprises a first external device comprising: at least one externalantenna configured to transmit a first transmission signal to theimplantable system, the first transmission signal comprising at leastpower or data; an external transmitter configured to drive the at leastone external antenna; an external power supply configured to providepower to at least the external transmitter; and an external controllerconfigured to control the external transmitter. The implantable systemcomprises a first implantable device comprising: at least oneimplantable antenna configured to receive the first transmission signalfrom the first external device; an implantable receiver configured toreceive the first transmission signal from the at least one implantableantenna; at least one implantable stimulation element configured todeliver stimulation energy to the patient; an implantable controllerconfigured to control the stimulation energy delivered to the at leastone implantable stimulation element; an implantable energy storageassembly configured to provide power to an element selected from thegroup consisting of: the at least one implantable stimulation element;the implantable controller; the implantable receiver; and combinationsthereof; and an implantable housing surrounding at least the implantablecontroller and the implantable receiver.

In some embodiments, the at least one implantable antenna is positionedoutside of the implantable housing, and the first implantable devicefurther comprises: one or more electrical components positioned withinthe implantable housing, and a tether that electrically connects the atleast one implantable antenna to the one or more electrical components.

In some embodiments, the first implantable device further comprises: oneor more functional elements positioned outside of the implantablehousing; one or more electrical components positioned within theimplantable housing; and a tether that electrically connects the one ormore functional elements to the one or more electrical components.

In some embodiments, the first external device is configured to bepositioned on the skin of the patient proximate the first implantabledevice, and the apparatus is configured to provide feedback regardingthe quality of the positioning of the first external device.

In some embodiments, the apparatus is configured to determine thequality of the first transmission signal by measuring the powerconsumption of the first external device. The position of the firstexternal device can be configured to be optimized based on thedetermined quality of the first transmission signal. The apparatus canbe further configured to determine the quality of the first transmissionusing a reference RSSI. The apparatus can compare the reference RSSI toa measured signal level of the first external device to determine thequality of the first transmission signal. The reference RSSI cancomprise a reference selected from the group consisting of: a referencedetermined during a manufacturing process of the apparatus; a referencebased on a characterization of a population of previously manufacturedexternal devices and implantable devices; a reference determined duringpatient use of the apparatus; a reference determined during acalibration process; and combinations thereof. The apparatus can furthercomprise one or more user output components, and the apparatus can befurther configured to provide feedback information related to thedetermined quality of the first transmission signal via the one or moreuser output components. The feedback information can comprise a good/badassessment. The feedback information can comprise a multi-levelassessment comprising three or more levels. The feedback information canbe used to optimize the position of the first external device on thepatient's skin. The feedback information can comprise the first externaldevice skin position information that can be indicated by a changinggraph, a changing quantity, and/or a changing tone.

In some embodiments, the first implantable device further comprises: oneor more implantable leads comprising the at least one stimulationelement, and the apparatus further comprises a trialing interfacecomprising: an electronic assembly; a first connector; and an interfaceconnector comprising a second connector removably attached to the firstconnector; and the interface connector is configured for operably andremovably attaching to the one or more implantable leads. The electronicassembly can comprise a first detection circuitry and the interfaceconnector can comprise a second detection circuitry, and the trialinginterface can be configured to detect proper connection of the firstconnector and the second connector via the first detection circuitry andthe second detection circuitry. The trialing interface can be configuredto repeatedly detect the proper connection. The second connector cancomprise multiple contacts, and the second detection circuitry cancomprise a connection of known resistance between two or more of themultiple contacts, and the electronic assembly can be configured todetect the proper connection based on the known resistance. The trialinginterface can be configured to detect the proper connection withoutusing a direct current signal. The trialing interface can be configuredto detect the proper connection using an alternating current signal. Thealternating current signal can comprise a digital pulse, and theelectronic assembly can be configured to detect a high state during thepulse and a low state after the pulse. The trialing interface can beconfigured to repeatedly detect the proper connection by repeatedlydelivering the digital pulse. The trialing interface can be configuredto detect the first connector and the second connector transitioningfrom a disconnected state to a connected state, and the apparatus can beconfigured to avoid full amplitude signal delivery to the patient at thetime of the connection. The apparatus can be configured to deliverstimulation energy at a first level prior to the time of the connection,and to initiate a new stimulation delivery in which the amplitude levelcan be slowly ramped up after the time of the connection. The amplitudecan be ramped up over a period of 1 second to 10 seconds.

In some embodiments, the apparatus further comprises a charging device,and the first external device comprises multiple electrical contactsconfigured to electrically connect to the charging device to receiveenergy to recharge the external power supply. The first external devicecan further comprise switching circuitry configured as a passivationmodule that reduces corrosion of the multiple electrical contacts. Theswitching circuitry can be configured to remove voltage from themultiple electrical contacts when the first external device is notoperably connected to the charging device. The switching circuitry cancomprise a first transistor which detects that the first external devicecan be operably connected to the charging device. The first externaldeice can be configured to detect an operable connection to the chargingdevice. The first external device can be configured to at least limittransmissions of power and/or data to the first implantable device whenthe first external device is operably connected to the charging device.The first external device can be configured to enter a sleep state whenthe first external device is operably connected to the charging device.

In some embodiments, the at least one stimulation element comprisesmultiple stimulation elements, and the first implantable device furthercomprises: one or more implantable leads, each lead comprising two ormore stimulation elements of the multiple stimulation elements, and thefirst implantable device does not comprise a monopolar return path forthe delivery of the stimulation energy by the multiple stimulationelements. The first implantable device can be configured to be in apseudo-monopolar mode, and to measure impedance of the multiplestimulation elements when in the pseudo-monopolar mode. Thepseudo-monopolar mode can comprise a first stimulation element of themultiple stimulation elements being configured as a cathode, and theremaining of the multiple stimulation elements each being configured asan anode. The first implantable device can comprise a current source,and the impedance associated with the first stimulation element can bedetermined by measuring a resulting voltage pulse that can be generatedat the first stimulation element when the current source delivers acurrent pulse to the first stimulation element. The pseudo-monopolarmode can comprise a second stimulation element of the multiplestimulation elements being configured as a cathode, and the remaining ofthe multiple stimulation elements each being configured as an anode. Theimpedance of the second stimulation element can be measured by measuringa resulting voltage pulse that is generated at the second stimulationelement when the current source delivers a current pulse to the secondstimulation element.

In some embodiments, the at least one stimulation element comprisesmultiple stimulation elements, and the first implantable device isconfigured to detect a short between a first stimulation element and asecond stimulation element. The first implantable device can furthercomprise a current source configured to deliver a current pulse to thefirst stimulation element while the first implantable device connectsthe remaining stimulation elements to ground, and the implantable devicedetects the short between the first stimulation element and the secondstimulation element if the resulting voltage is below a threshold. Thefirst implantable device can further comprise a current sourceconfigured to deliver a current pulse to the first stimulation element,and the implantable device detects the short between the firststimulation element and the second stimulation element if the resultingvoltage is above a threshold.

In some embodiments, the at least one stimulation element comprisesmultiple stimulation elements, and the first implantable device isconfigured to detect an open circuit at a stimulation element.

In some embodiments, the apparatus is configured such that the one ormore transmission signals are relatively unaffected by a rotationalorientation of the first external device.

In some embodiments, the at least one stimulation element is configuredto deliver a sequence of monophasic pulses. The at least one stimulationelement can comprise multiple stimulation elements configured to deliverstimulation energy to multiple tissue locations sequentially. Themonophasic pulses can be sequenced within the stimulation interval perthe pulse width and inter-pulse gaps for each tissue location.

In some embodiments, the first implantable device is configured toincrease compliance voltage and to perform passive charge recovery.

The technology described herein, along with the attributes and attendantadvantages thereof, will best be appreciated and understood in view ofthe following detailed description taken in conjunction with theaccompanying drawings in which representative embodiments are describedby way of example.

INCORPORATION BY REFERENCE

All publications, patents, and patent applications mentioned in thisspecification are herein incorporated by reference to the same extent asif each individual publication, patent, or patent application wasspecifically and individually indicated to be incorporated by reference.The content of all publications, patents, and patent applicationsmentioned in this specification are herein incorporated by reference intheir entirety for all purposes.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing and other objects, features and advantages of embodimentsof the present inventive concepts will be apparent from the moreparticular description of preferred embodiments, as illustrated in theaccompanying drawings in which like reference characters refer to thesame or like elements. The drawings are not necessarily to scale,emphasis instead being placed upon illustrating the principles of thepreferred embodiments.

FIG. 1 is a schematic anatomical view of a medical apparatus comprisingan external system and an implantable system, consistent with thepresent inventive concepts.

FIG. 2 is a flow chart of a method for positioning an external device onthe skin of a patient, consistent with the present inventive concepts.

FIGS. 3A-D are various views of a patient attachment device and anexternal device, consistent with the present inventive concepts.

FIGS. 4A-B are perspective views of an electronic assembly of animplantable device in unfolded and folded states, respectively,consistent with the present inventive concepts.

FIGS. 5A-H are various views of an electronic assembly of an implantabledevice in various states of a folding process, consistent with thepresent inventive concepts.

FIGS. 6A-C are a perspective, end, and side view, respectively, of apartially assembled portion of an implantable device, consistent withthe present inventive concepts.

FIGS. 7A-C are a perspective, top, and side view, respectively, of animplantable device including a connector for attaching to two leads,consistent with the present inventive concepts.

FIG. 7D is a top view of the end portion of the connector of FIGS. 7A-C.

FIGS. 8A-C are a perspective, side sectional, and perspectivetransparent view, respectively, of an anchoring element, consistent withthe present inventive concepts.

FIG. 9 is a top view of an electronic assembly of an implantable device,consistent with the present inventive concepts.

FIG. 10 is an exploded view of an external device, consistent with thepresent inventive concepts.

FIGS. 11A-D are a perspective top view, a side view, a side sectionalview, and another side sectional view, respectively, of an interfaceassembly for operably attaching a trialing interface to two leadassemblies, consistent with the present inventive concepts.

FIGS. 12A-B are a perspective view and a schematic view, respectively,of a stimulation apparatus comprising a trialing interface and a leadconnector, consistent with the present inventive concepts.

FIGS. 13A-B are perspective views and a top view, respectively, of animplantable device with a single lead, and an implantable device withdual leads, respectively, consistent with the present inventiveconcepts.

FIG. 13C is a top view of an implantable device with dual leads andseparate implantation tools inserted into each lead, consistent with thepresent inventive concepts.

FIGS. 14A-B are a perspective view and a top view, respectively, of theproximal portion of an implantable device with dual leads, consistentwith the present inventive concepts.

FIGS. 15A-M are a series of views of various implantation procedures foran implantable device, consistent with the present inventive concepts.

FIGS. 16A-B are a side view of an introducer tool, and a magnified viewof the distal portion of the introducer tool, respectively, consistentwith the present inventive concepts.

FIGS. 17A-C are various views of an external device and a chargingdevice, consistent with the present inventive concepts.

FIG. 17D is a schematic view of charging circuitry for an externaldevice, consistent with the present inventive concepts.

FIG. 18 is a schematic view of a portion of an electronic assembly of animplantable device, consistent with the present inventive concepts.

FIG. 19 is a block diagram of a TTAP system, consistent with the presentinventive concepts.

FIGS. 20A-B are schematic views of a power delivery and consumptionarrangement of a stimulation apparatus, consistent with the presentinventive concepts.

FIG. 21 is a schematic view of a back-telemetry circuit of animplantable device, consistent with the present inventive concepts.

FIGS. 22A-F are schematic views of various implantable device leadarrangements, consistent with the present inventive concepts.

FIG. 23 is a graph of an amplitude modulation scheme, consistent withthe present inventive concepts.

FIGS. 24A-B are top views of an external device positioned on a patientin a first orientation, and a second orientation, respectively,consistent with the present inventive concepts.

FIG. 25A is a schematic view of a reconfigurable stimulation blockportion of an electronic assembly of an implantable device, consistentwith the present inventive concepts.

FIG. 25B is a diagram of a control input sequence, consistent with thepresent inventive concepts.

FIG. 25C is a schematic view of a portion of an electronic assembly ofan implantable device, consistent with the present inventive concepts.

FIGS. 26A-C are schematic views of a test fixture arrangement fortesting an electronic assembly of an implantable device, consistent withthe present inventive concepts.

FIGS. 27A-C are a series of views of stimulations waveforms, consistentwith the present inventive concepts.

FIGS. 28A-C are schematic views of stimulation circuitry of animplantable device, consistent with the present inventive concepts.

FIGS. 28D-E are views of stimulation and discharge waveforms, consistentwith the present inventive concepts.

FIGS. 28F-G are views of stimulation and discharge waveforms, as well asa chart of voltage across a DC blocking capacitor, consistent with thepresent inventive concepts.

DETAILED DESCRIPTION OF THE DRAWINGS

The terminology used herein is for the purpose of describing particularembodiments and is not intended to be limiting of the inventiveconcepts. Furthermore, embodiments of the present inventive concepts mayinclude several novel features, no single one of which is solelyresponsible for its desirable attributes or which is essential topracticing an inventive concept described herein. As used herein, thesingular forms “a,” “an” and “the” are intended to include the pluralforms as well, unless the context clearly indicates otherwise.

It will be further understood that the words “comprising” (and any formof comprising, such as “comprise” and “comprises”), “having” (and anyform of having, such as “have” and “has”), “including” (and any form ofincluding, such as “includes” and “include”) or “containing” (and anyform of containing, such as “contains” and “contain”) when used herein,specify the presence of stated features, integers, steps, operations,elements, and/or components, but do not preclude the presence oraddition of one or more other features, integers, steps, operations,elements, components, and/or groups thereof.

It will be understood that, although the terms first, second, third etc.may be used herein to describe various limitations, elements,components, regions, layers, and/or sections, these limitations,elements, components, regions, layers, and/or sections should not belimited by these terms. These terms are only used to distinguish onelimitation, element, component, region, layer or section from anotherlimitation, element, component, region, layer or section. Thus, a firstlimitation, element, component, region, layer or section discussed belowcould be termed a second limitation, element, component, region, layeror section without departing from the teachings of the presentapplication.

It will be further understood that when an element is referred to asbeing “on”, “attached”, “connected” or “coupled” to another element, itcan be directly on or above, or connected or coupled to, the otherelement, or one or more intervening elements can be present. Incontrast, when an element is referred to as being “directly on”,“directly attached”, “directly connected” or “directly coupled” toanother element, there are no intervening elements present. Other wordsused to describe the relationship between elements should be interpretedin a like fashion (e.g. “between” versus “directly between,” “adjacent”versus “directly adjacent,” etc.). A first component (e.g. a device,assembly, housing or other component) can be “attached”, “connected” or“coupled” to another component via a connecting filament (as definedbelow). In some embodiments, an assembly comprising multiple componentsconnected by one or more connecting filaments is created during amanufacturing process (e.g. pre-connected at the time of an implantationprocedure of the apparatus of the present inventive concepts).Alternatively or additionally, a connecting filament can comprise one ormore connectors (e.g. a connectorized filament comprising a connector onone or both ends), and a similar assembly can be created by a user (e.g.a clinician) operably attaching the one or more connectors of theconnecting filament to one or more mating connectors of one or morecomponents of the assembly.

It will be further understood that when a first element is referred toas being “in”, “on” and/or “within” a second element, the first elementcan be positioned: within an internal space of the second element,within a portion of the second element (e.g. within a wall of the secondelement); positioned on an external and/or internal surface of thesecond element; and combinations of one or more of these.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper” and the like may be used to describe an element and/or feature'srelationship to another element(s) and/or feature(s) as, for example,illustrated in the figures. It will be understood that the spatiallyrelative terms are intended to encompass different orientations of thedevice in use and/or operation in addition to the orientation depictedin the figures. For example, if the device in a figure is turned over,elements described as “below” and/or “beneath” other elements orfeatures would then be oriented “above” the other elements or features.The device can be otherwise oriented (e.g. rotated 90 degrees or atother orientations) and the spatially relative descriptors used hereininterpreted accordingly.

As used herein, the term “proximate” shall include locations relativelyclose to, on, in, and/or within a referenced component or otherlocation.

The term “and/or” where used herein is to be taken as specificdisclosure of each of the two specified features or components with orwithout the other. For example, “A and/or B” is to be taken as specificdisclosure of each of (i) A, (ii) B and (iii) A and B, just as if eachis set out individually herein.

The term “diameter” where used herein to describe a non-circulargeometry is to be taken as the diameter of a hypothetical circleapproximating the geometry being described. For example, when describinga cross section, such as the cross section of a component, the term“diameter” shall be taken to represent the diameter of a hypotheticalcircle with the same cross-sectional area as the cross section of thecomponent being described.

The terms “major axis” and “minor axis” of a component where used hereinare the length and diameter, respectively, of the smallest volumehypothetical cylinder which can completely surround the component.

The term “functional element” where used herein, is the be taken toinclude a component comprising one, two or more of: a sensor; atransducer; an electrode; an energy delivery element; an agent deliveryelement; a magnetic field generating transducer; and combinations of oneor more of these. In some embodiments, a functional element comprises atransducer selected from the group consisting of: light deliveryelement; light emitting diode; wireless transmitter; Bluetooth device;mechanical transducer; piezoelectric transducer; pressure transducer;temperature transducer; humidity transducer; vibrational transducer;audio transducer; speaker; and combinations of one or more of these. Insome embodiments, a functional element comprises a needle, a catheter(e.g. a distal portion of a catheter), an iontophoretic element or aporous membrane, such as an agent delivery element configured to deliverone or more agents. In some embodiments, a functional element comprisesone or more sensors selected from the group consisting of: electrode;sensor configured to record electrical activity of tissue; blood glucosesensor such as an optical blood glucose sensor; pressure sensor; bloodpressure sensor; heart rate sensor; inflammation sensor; neural activitysensor; muscular activity sensor; pH sensor; strain gauge;accelerometer; gyroscope; GPS; respiration sensor; respiration ratesensor; temperature sensor; magnetic sensor; optical sensor; MEMssensor; chemical sensor; hormone sensor; impedance sensor; tissueimpedance sensor; body position sensor; body motion sensor; physicalactivity level sensor; perspiration sensor; patient hydration sensor;breath monitoring sensor; sleep monitoring sensor; food intakemonitoring sensor; urine movement sensor; bowel movement sensor; tremorsensor; pain level sensor; orientation sensor; motion sensor; andcombinations of one or more of these.

The term “transducer” where used herein is to be taken to include anycomponent or combination of components that receives energy or anyinput, and produces an output. For example, a transducer can include anelectrode that receives electrical energy, and distributes theelectrical energy to tissue (e.g. based on the size of the electrode).In some configurations, a transducer converts an electrical signal intoany output, such as light (e.g. a transducer comprising a light emittingdiode or light bulb), sound (e.g. a transducer comprising a piezocrystal configured to deliver ultrasound energy), pressure, heat energy,cryogenic energy, chemical energy, mechanical energy (e.g. a transducercomprising a motor or a solenoid), magnetic energy, and/or a differentelectrical signal (e.g. a Bluetooth or other wireless communicationelement). Alternatively or additionally, a transducer can convert aphysical quantity (e.g. variations in a physical quantity) into anelectrical signal. A transducer can include any component that deliversenergy and/or an agent to tissue, such as a transducer configured todeliver one or more of: electrical energy to tissue (e.g. a transducercomprising one or more electrodes); light energy to tissue (e.g. atransducer comprising a laser, light emitting diode and/or opticalcomponent such as a lens or prism); mechanical energy to tissue (e.g. atransducer comprising a tissue manipulating element); sound energy totissue (e.g. a transducer comprising a piezo crystal); thermal energy totissue (e.g. heat energy and/or cryogenic energy); chemical energy;electromagnetic energy; magnetic energy; and combinations of one or moreof these.

The term “transmission signal” where used herein is to be taken toinclude any signal transmitted between two components, such as via awired or wireless communication pathway. For example, a transmissionsignal can comprise a power and/or data signal wirelessly transmittedbetween a component external to the patient and one or more componentsimplanted in the patient. A transmission signal can include one or moresignals transmitted using body conduction. Alternatively oradditionally, a transmission signal can comprise reflected energy, suchas energy reflected from any power and/or data signal.

The term “data signal” where used herein is to be taken to include atransmission signal including at least data. For example, a data signalcan comprise a transmission signal including data and sent between acomponent external to the patient and one or more components implantedin the patient. Alternatively, a data signal can comprise a transmissionsignal including data sent from an implanted component to one or morecomponents external to the patient. A data signal can comprise aradiofrequency signal including data (e.g. a radiofrequency signalincluding both power and data) and/or a data signal sent using bodyconduction.

The term “implantable” where used herein is to be taken to define acomponent which is constructed and arranged to be fully or partiallyimplanted in a patient's body and/or a component that has been fully orpartially implanted in a patient. The term “external” where used hereinis to be taken to define a component which is constructed and arrangedto be positioned outside of the patient's body.

The terms “attachment”, “attached”, “attaching”, “connection”,“connected”, “connecting” and the like, where used herein, are to betaken to include any type of connection between two or more components.The connection can include an “operable connection” or “operableattachment” which allows multiple connected components to operatetogether such as to transfer information, power, and/or material (e.g.an agent to be delivered) between the components. An operable connectioncan include a physical connection, such as a physical connectionincluding a connection between two or more: wires or other conductors(e.g. an “electrical connection”), optical fibers, wave guides, tubessuch as fluid transport tubes, and/or linkages such as translatable rodsor other mechanical linkages. Alternatively or additionally, an operableconnection can include a non-physical or “wireless” connection, such asa wireless connection in which information and/or power is transmittedbetween components using electromagnetic energy. A connection caninclude a connection selected from the group consisting of: a wiredconnection; a wireless connection; an electrical connection; amechanical connection; an optical connection; a sound propagatingconnection; a fluid connection; and combinations of one or more ofthese.

The term “connecting filament” where used herein is to be taken todefine a filament connecting a first component to a second component.The connecting filament can include a connector on one or both ends,such as to allow a user to operably attach at least one end of thefilament to a component. A connecting filament can comprise one or moreelements selected from the group consisting of: wires; optical fibers;fluid transport tubes; mechanical linkages; wave guides; flexiblecircuits; and combinations of one or more of these. A connectingfilament can comprise rigid filament, a flexible filament or it cancomprise one or more flexible portions and one or more rigid portions.

The term “connectorized” where used herein is to be taken to refer to afilament, housing or other component that includes one or moreconnectors (e.g. clinician or other user-attachable connectors) foroperably connecting that component to a mating connector (e.g. of thesame or different component).

The terms “stimulation parameter”, “stimulation signal parameter” or“stimulation waveform parameter” where used herein can be taken to referto one or more parameters of a stimulation waveform (also referred to asa stimulation signal). Applicable stimulation parameters of the presentinventive concepts shall include but are not limited to: amplitude (e.g.amplitude of voltage and/or current); average amplitude; peak amplitude;frequency; average frequency; pulse width (also referred to as “pulsepattern on time”); period; phase; polarity; pulse shape; a duty cycleparameter (e.g. frequency, pulse width, and/or off time); inter-pulsegap (also referred to as “pulse pattern off time”, or “inter-pulseinterval”); polarity; burst-on (also referred to as “dosage on”) period;burst-off (also referred to as “dosage off”) period; inter-burst period;pulse train; train-on period; train-off period; inter-train period;drive impedance; duration of pulse and/or amplitude level; duration ofstimulation waveform; repetition of stimulation waveform; an amplitudemodulation parameter; a frequency modulation parameter; a burstparameter; a power spectral density parameter; an anode/cathodeconfiguration parameter; amount of energy and/or power to be delivered;rate of energy and/or power delivery; time of energy deliveryinitiation; method of charge recovery; and combinations of one or moreof these. A stimulation parameter can refer to a single stimulationpulse, multiple stimulation pulses, or a portion of a stimulation pulse.The term “amplitude” where used herein can refer to an instantaneous orcontinuous amplitude of one or more stimulation pulses (e.g. theinstantaneous voltage level or current level of a pulse). The term“pulse” where used herein can refer to a period of time during whichstimulation energy is relatively continuously being delivered. In someembodiments, stimulation energy delivered during a pulse comprisesenergy selected from the group consisting of: electrical energy;magnetic energy; electromagnetic energy; light energy; sound energy suchas ultrasound energy; mechanical energy such as vibrational energy;thermal energy such as heat energy or cryogenic energy; chemical energy;and combinations of one or more of these. In some embodiments,stimulation energy comprises electrical energy and a pulse comprises aphase change in current and/or voltage. In these embodiments, an“inter-phase gap” can be present within a single pulse. The terminter-phase gap where used herein can refer to a period of time betweentwo portions of a pulse comprising a phase change during which zeroenergy or minimal energy is delivered. The term “quiescent period” whereused herein can refer to a period of time during which zero energy orminimal energy is delivered (e.g. insufficient energy to elicit anaction potential and/or other neuronal response). The term “inter-pulsegap” where used herein can refer to a quiescent period between the endof one pulse to the onset of the next (sequential) pulse. The terms“pulse train” or “train” where used herein can refer to a series ofpulses. The terms “burst”, “burst of pulses” or “burst stimulation”where used herein can refer to a series of pulse trains, each separatedby a quiescent period. The term “train-on period” where used herein canrefer to a period of time from the beginning of the first pulse to theend of the last pulse of a single train. The term “train-off period”where used herein can refer to a quiescent period between the end of onetrain and the beginning of the next train. The term “burst-on period”where used herein can refer to a period of time from the beginning ofthe first pulse of the first train to the end of the last pulse of thelast train of a single burst. The term “burst-off period” where usedherein can refer to a quiescent period between the end of one burst andthe beginning of the next burst. The term “inter-train period” whereused herein can refer to a quiescent period between the end of one trainand the beginning of the next train. The term “inter-burst period” whereused herein can refer to a quiescent period between the end of one burstand the beginning of the next burst. The term “train envelope” whereused herein can refer to a curve outlining the amplitude extremes of aseries of pulses in a train. The term “burst envelope” where used hereincan refer to a curve outlining the amplitude extremes of a series ofpulses in a burst. The term “train ramp duration” where used herein canrefer to the time from the onset of a train until its train envelopereaches a desired target magnitude. The term “burst ramp duration” whereused herein can refer to the time from the onset of a burst until itsburst envelope reaches a desired target magnitude.

It is appreciated that certain features of the invention, which are, forclarity, described in the context of separate embodiments, may also beprovided in combination in a single embodiment. Conversely, variousfeatures of the invention which are, for brevity, described in thecontext of a single embodiment, may also be provided separately or inany suitable sub-combination. For example, it will be appreciated thatall features set out in any of the claims (whether independent ordependent) can be combined in any given way.

The present inventive concepts include a medical apparatus and clinicalmethods for treating a patient, such as to treat pain. The patient cancomprise a human or other mammalian patient. The medical apparatus cancomprise a stimulation apparatus. The medical apparatus can comprise animplantable system and an external system. The implantable system cancomprise one or more similar and/or dissimilar implantable devices. Eachimplantable device comprises a housing surrounding one or morestimulation producing components. A lead comprising one or morestimulation elements can be pre-attached to the housing, or attachableto the housing (e.g. attached in a clinical procedure in which theimplantable device is implanted in a patient).

The apparatus can include a trialing interface which provides energy tothe stimulation elements during the implantation procedure, such as toconfirm proper placement of the stimulation elements and/or to titratethe stimulation delivered. In embodiments in which the lead ispre-attached to the housing of the implantable device, the trialinginterface can be configured to provide power (e.g. wireless power) tothe implantable device, the implantable device providing stimulationenergy to the stimulation elements derived from the power provided bythe trialing interface. In embodiments in which the lead is attachableto the housing of the implantable device, the trialing interface canattach to the lead (prior to its attachment to the housing of theimplantable device), and the trialing interface can then provide thestimulation energy directly to the stimulation elements.

In some embodiments, the implantable system comprises a firstimplantable device that delivers stimulation energy via energy receivedwirelessly from one or more external devices, and a second implantabledevice that delivers stimulation energy via an integral (e.g. implanted)battery. In these embodiments, the first implantable device can beconfigured to deliver stimulation energy during a limited period of time(e.g. a trial period in which stimulation settings are determined and/oracceptability of the apparatus is determined), and the secondimplantable device can be configured to deliver stimulation energy for aprolonged period of time in which long-term stimulation therapy isprovided to a patient. In these embodiments, a single implantable leadcomprising one or more stimulation energy delivery elements (e.g.electrodes) can be connected to the first implantable device and thenthe second implantable device. In some embodiments, a first implantabledevice can be configured to remain implanted in the patient for alimited period of time, such as to reduce cost of manufacture, and asecond implantable device is configured for a longer implant life. Thefirst implantable device can be used in a trialing procedure in whichthe stimulation apparatus is assessed for acceptable use (e.g. by thepatient and/or clinician) and/or one or more stimulation settings areoptimized or otherwise determined.

Each implantable device can comprise one or more implantable antennasconfigured to receive power and/or data. Each implantable device cancomprise an implantable receiver configured to receive the power and/ordata from the one or more implantable antennas. Each implantable devicecan comprise one or more implantable functional elements (e.g. animplantable stimulation element). An implantable functional element canbe configured to interface with the patient (e.g. interface with tissueof the patient or interface with any patient location). Alternatively oradditionally, an implantable functional element can interface with aportion of an implantable device (e.g. to measure an implantable deviceparameter). In some embodiments, the one or more implantable functionalelements can comprise one or more transducers, electrodes, and/or otherelements configured to deliver energy to tissue. Alternatively oradditionally, the one or more implantable functional elements cancomprise one or more sensors, such as a sensor configured to record aphysiologic parameter of the patient. In some embodiments, one or moreimplantable functional elements are configured to record deviceinformation and/or patient information (e.g. patient physiologic orpatient environment information).

Each implantable device can comprise an implantable controllerconfigured to control (e.g. modulate power to, send a signal to, and/orreceive a signal from) the one or more implantable functional elements.In some embodiments, an implantable controller of a first implantabledevice is configured to control one or more other implantable devices.Each implantable device can comprise an implantable energy storageassembly (e.g. a battery and/or a capacitor) configured to provide powerto the implantable controller (e.g. a controller comprising astimulation waveform generator), the implantable receiver and/or the oneor more implantable functional elements. In some embodiments, animplantable energy storage assembly is further configured to providepower to an assembly that transmits signals via the implantable antenna(e.g. when the implantable device is further configured to transmit datato one or more external devices). Each implantable device can comprisean implantable housing surrounding the implantable controller and theimplantable receiver. In some embodiments, one or more implantableantennas are positioned within the implantable housing. Alternatively oradditionally, one or more implantable antennas and/or implantablefunctional elements can be positioned outside the implantable housing,and tethered (e.g. electrically tethered) to one or more electricalcomponents of the implantable device positioned within the implantablehousing. In some embodiments, one or more implantable functionalelements are positioned on an implantable lead, such as a flexible leadmechanically fixed or attachable to the implantable housing and operablyconnected (e.g. electrically, fluidly, optically and/or mechanically) toone or more components internal to the implantable housing. Theimplantable lead can be inserted (e.g. tunneled) through tissue of thepatient, such that its one or more functional elements are positionedproximate tissue to be treated and/or positioned at an area in whichdata is to be recorded. In some embodiments, the implantable lead isconfigured to operably attach to and/or detach from, multipleimplantable devices.

The external system of the medical apparatus of the present inventiveconcepts can comprise one or more similar and/or dissimilar externaldevices. Each external device can comprise one or more external antennasconfigured to transmit power and/or data to one or more implantedcomponents of the implantable system. Each external device can comprisean external transmitter configured to drive the one or more externalantennas. Each external device can comprise an external power supplyconfigured to provide power to at least the external transmitter. Eachexternal device can comprise an external programmer configured tocontrol the external transmitter and/or an implantable device (e.g. whenan external power transmitter is not included in the apparatus orotherwise not present during use). Each external device can comprise anexternal housing that surrounds at least the external transmitter. Insome embodiments, the external housing surrounds the one or moreexternal antennas, the external power supply and/or the externalprogrammer.

The external programmer can comprise a discrete controller separate fromthe one or more external devices, and/or a controller integrated intoone or more external devices. The external programmer can comprise auser interface, such as a user interface configured to set and/or modifyone or more treatment and/or data recording settings of the medicalapparatus of the present inventive concepts. In some embodiments, theexternal programmer is configured to collect and/or diagnose recordedpatient information, such as to provide the information and/or diagnosisto a clinician of the patient, to a patient family member and/or to thepatient themselves. The collected information and/or diagnosis can beused to adjust treatment or other operating parameters of the medicalapparatus. In some embodiments, at least two external programmers areincluded, such as a first external programmer configured for use by thepatient, and a second external programmer configured for use by aclinician of the patient.

In some embodiments, a medical apparatus comprises a stimulationapparatus for activating, blocking, affecting or otherwise stimulating(hereinafter “stimulate” or “stimulating”) tissue of a patient, such asnerve tissue or nerve root tissue (hereinafter “nerve”, “nerves”, “nervetissue” or “nervous system tissue”). The stimulation apparatus comprisesan external system configured to transmit power, and an implanted systemconfigured to receive the power from the external system and to deliverstimulation energy to tissue. The delivered stimulation energy cancomprise one or more stimulation waveforms, such as a stimulationwaveform configured to enhance treatment of pain while minimizingundesired effects. The stimulation signal (also referred to as“stimulation energy” herein) delivered by the implanted system can beindependent of the power received from the external system, such as tobe independent of one or more of: the position of one or more componentsof the external system; the changing position of one or more componentsof the external system; the frequency of the power received from theexternal system; the amplitude of the power received from the externalsystem; changes in amplitude of the power received from the externalsystem; duty cycle of the power received from the external system;envelope of the power received from the external system; andcombinations of one or more of these.

Referring now to FIG. 1, a schematic anatomical view of a stimulationapparatus for providing a therapy to a patient is illustrated,consistent with the present inventive concepts. Apparatus 10 comprisesimplantable system 20 and external system 50. External system 50transmits transmission signals to one or more components of implantablesystem 20. These transmission signals can comprise power and/or data.Implantable system 20 comprises implantable device 200 shown implantedbeneath the skin of patient P. In some embodiments, implantable system20 comprises multiple similar or dissimilar implantable devices 200(singly or collectively implantable device 200), such as is described inapplicant's co-pending U.S. patent application Ser. No. 16/104,829,titled “Apparatus with Enhanced Stimulation Waveforms”, filed Aug. 17,2018 [Docket nos. 47476-708.301; NAL-014-US]. Each implantable device200 can be configured to receive power and data from a transmissionsignal transmitted by external system 50, such as when stimulationenergy delivered to the patient (e.g. to nerve or other tissue of thepatient) by implantable device 200 is provided via wirelesstransmissions signals from external system 50. In some embodiments,implantable system 20 comprises at least two implantable devices, suchas implantable device 200 and implantable device 200′ shown in FIG. 1.Implantable device 200′ can be of similar construction and arrangementto implantable device 200, and it can include components of a differentconfiguration. Each implantable device 200 comprises one or morehousings, housing 210 shown, which surrounds various other components ofdevice 200. Each implantable device 200 comprises one or morestimulation and/or other functional elements, such as stimulationelement 260 shown, where stimulation elements 260 are configured todeliver stimulation energy, a stimulating drug or other agent, and/oranother form of stimulation (e.g. another form of tissue stimulation) tothe patient. In some embodiments, one or more stimulation elements 260are further configured as a sensor (e.g. when comprising an electrodeconfigured to both deliver electrical energy and record electricalsignals). Each implantable device 200 can include one or more leads,lead 265 shown, and each lead 265 can include one or more stimulationelements 260. Alternatively or additionally, one or more stimulationelements 260 can be positioned on housing 210 or one or more othercomponents of implantable device 200.

Each implantable device 200 can comprise one or more other types offunctional elements, such as functional element 299 a shown positionedproximate housing 210 (e.g. within and/or on the external surface ofhousing 210) and/or functional element 299 b shown positioned on lead265. Functional element 299 a and/or 299 b (singly or collectivelyfunctional element 299) can comprise a transducer, a sensor, and/orother functional element as described herein. In some embodiments, afunctional element 299 comprises a visualizable marker, such as aradiopaque marker, an ultrasonically visible marker, and/or a magneticmarker.

External system 50 can comprise an external device 500, which includesone or more housings, housing 510 shown, which surrounds various othercomponents of device 500. In some embodiments, external system 50comprises multiple external devices 500 (singly or collectively externaldevice 500), such as an external device as is described in applicant'sco-pending U.S. patent application Ser. No. 16/104,829, titled“Apparatus with Enhanced Stimulation Waveforms”, filed Aug. 17, 2018[Docket nos. 47476-708.301; NAL-014-US]. In some embodiments, externalsystem 50 comprises at least two, or at least three external devices(e.g. at least two external devices configured to deliver power and/ordata to one or more implantable devices 200), such as external device500, external device 500′, and external device 500″ shown in FIG. 1.External device 500′ and/or 500″ can be of similar construction andarrangement to external device 500, and these devices can includecomponents of a different configuration.

External system 50 can comprise one or more programming devices,programmer 600, such as patient programmer 600′ and clinician programmer600″ shown. Patient programmer 600′ and clinician programmer 600″(singly or collectively programmer 600) each comprise a user interface,such as user interfaces 680′ and 680″ shown (singly or collectively userinterface 680). Programmer 600 can be configured to control one or moreexternal devices 500. Alternatively or additionally, programmer 600 canbe configured to control one or more implantable devices 200 (e.g. whenno external device 500 is included in apparatus 10 or at least noexternal device 500 is available to communicate with an implantabledevice 200). Patient programmer 600′ can be configured to be used by thepatient, patient caregiver (e.g. clinician of the patient), and/or afamily member of the patient.

Clinician programmer 600″ can be of similar construction and arrangementto patient programmer 600′. In some embodiments, clinician programmer600″ provides additional functions not available in patient programmer600′. In some embodiments, clinician programmer 600″ can modify theprogramming of patient programmer 600′ (e.g. modify the programmingoptions available to the patient or family member of the patient).

Patient programmer 600′ can be further configured as a smart phoneand/or a music playing device (e.g. an mp3 player). For example, patientprogrammer 600′ can comprise a smart phone or other commercial deviceonto which a software program of apparatus 10 is embedded to cause thecommercial device to function as patient programmer 600′. Clinicianprogrammer 600″ can comprise a tablet-like device. For example,clinician programmer 600″ can comprise a commercial tablet device ontowhich a software program of apparatus 10 is embedded to cause thecommercial tablet to function as clinician programmer 600″.

Clinician programmer 600″ can configure multiple (e.g. all) externaldevices 500 used by a patient, as well as patient programmer 600′, sothat the set of devices are configured as a “trusted” network. Afterthis configuration, patient programmer 600′ can safely and effectivelycommunicate with the one or more external devices 500 of the patient.The patient programmer 600′ can upload (e.g. automatically upload)configuration information from an external device 500 (e.g. stimulationsettings and the like). In some embodiments, patient programmer 600′and/or clinician programmer 600″ uploads configuration information froman external device 500 any time certain information (e.g. stimulationinformation) on that external device 500 has changed (e.g. a change isdetected by the programmer 600 or otherwise).

External system 50 can comprise one, two, three, or more functionalelements, such as functional elements 599 a, 599 b, and/or 599 c (singlyor collectively functional element 599), shown positioned in externaldevice 500, patient programmer 600′, and clinician programmer 600″,respectively.

Apparatus 10 can be configured to stimulate tissue (e.g. stimulate nervetissue such as tissue of the central nervous system or tissue of theperipheral nervous system, such as to neuromodulate nerve tissue), suchas by having one or more implantable devices 200 deliver and/orotherwise provide energy (hereinafter “deliver energy”) and/or deliveran agent (e.g. a pharmaceutical compound or other agent) to one or moretissue locations, such as via one or more stimulation elements 260. Insome embodiments, one or more implantable devices 200 deliver energyand/or an agent while receiving power and/or data from one or moreexternal devices 500. In some embodiments, one or more implantabledevices 200 deliver energy and/or an agent (e.g. continuously orintermittently) using energy provided by an internal power source (e.g.a battery and/or capacitor) without receiving externally supplied power,such as for periods of at least 1 hour, at least 1 day, at least 1 monthor at least 1 year. In some embodiments, one or more stimulationparameters are varied (e.g. systematically and/or randomly), during thatperiod.

In some embodiments, apparatus 10 is further configured as a patientdiagnostic apparatus, such as by having one or more implantable devices200 record a patient parameter (e.g. a patient physiologic parameter)from one or more tissue locations, such as while receiving power and/ordata from one or more external devices 500. In some embodiments, duringits use, one or more implantable devices 200 at least receives powerfrom one or more external devices 500 (e.g. with or without alsoreceiving data). Alternatively or additionally, one or more patientparameters can be recorded by an external device of apparatus 10, suchas via a programmer 600 and/or an external device 500.

Apparatus 10 can be configured as a patient information recordingapparatus, such as by having one or more implantable devices 200 and/orone or more external devices 500 record patient information (e.g.patient physiologic information and/or patient environment information).In some embodiments, one or more implantable devices 200 and/or one ormore external devices 500 further collect information (e.g. statusinformation or configuration settings) of one or more of the componentsof apparatus 10.

In some embodiments, apparatus 10 is configured to deliver stimulationenergy to tissue to treat pain. In particular, apparatus 10 can beconfigured to deliver stimulation energy to tissue of the spinal cordand/or tissue associated with the spinal cord (“tissue of the spinalcord”, “spinal cord tissue” or “spinal cord” herein), the tissueincluding roots, dorsal root, dorsal root ganglia, spinal nerves,ganglia, and/or other nerve tissue. The delivered energy can compriseenergy selected from the group consisting of: electrical energy;magnetic energy; electromagnetic energy; light energy such as infraredlight energy, visible light energy and/or ultraviolet light energy;mechanical energy; thermal energy such as heat energy and/or cryogenicenergy; sound energy such as ultrasonic sound energy (e.g. highintensity focused ultrasound and/or low intensity focused ultrasound)and/or subsonic sound energy; chemical energy; and combinations of oneor more of these. In some embodiments, apparatus 10 is configured todeliver to tissue energy in a form selected from the group consistingof: electrical energy such as by providing a controlled (e.g. constantor otherwise controlled) electrical current and/or voltage to tissue;magnetic energy (e.g. magnetic field energy) such as by applyingcontrolled current or voltage to a coil or other magnetic fieldgenerating element positioned proximate tissue; and/or electromagneticenergy such as by providing both current to tissue and a magnetic fieldto tissue. A coil or other magnetic field generating element cansurround (e.g. at least partially surround) the target nerve.Alternatively, or additionally, the magnetic energy can be appliedexternally and focused to specific target tissue via an implantcomprising a coil and/or ferromagnetic materials. In some embodiments,the magnetic energy is configured to induce the application ofmechanical energy. Delivered energy can be supplied in one or morestimulation waveforms, each waveform comprising one or more pulses ofenergy, as described in detail herebelow.

In some embodiments, apparatus 10 is configured as a stimulationapparatus in which external system 50 transmits a power signal to one ormore implantable devices 200, and the one or more implantable devices200 deliver stimulation energy to tissue with a stimulation signal (alsoreferred to as a stimulation waveform), with the power signal and thestimulation signal having one or more different characteristics (e.g. asdescribed herebelow). The power signal can be modulated with data (e.g.configuration or other data to be sent to one or more implantabledevices 200). In these embodiments, the characteristics of thestimulation signal delivered (e.g. amplitude, frequency, duty cycleand/or pulse width), can be independent (e.g. partially or completelyindependent) of the characteristics of the power signal transmission(e.g. amplitude, frequency, phase, envelope, duty cycle and/ormodulation). For example, the frequency and modulation of the powersignal can change without affecting those or other parameters of thestimulation signal, and/or the parameters of the stimulation signal canbe changed (e.g. via programmer 600), without requiring similar or anychanges to the power signal. In some embodiments, implantable system 20is configured to rectify the received power signal, and to produce astimulation waveform with entirely different characteristics (e.g.amplitude, frequency and/or duty cycle) from the rectified power signal.Each implantable device 200 can comprise an oscillator and/or controllerconfigured to produce the stimulation signal. In some embodiments, oneor more implantable devices 200 is configured to perform frequencymultiplication, in which multiple signals are multiplexed, mixed, added,and/or combined in other ways to produce a broadband stimulation signal.

In some embodiments, apparatus 10 is configured such that externalsystem 50 transmits data (e.g. data and power) to implantable system 20,and implantable system 20 recovers (e.g. decodes, demodulates orotherwise recovers) the transmitted data without synchronizing to thecarrier and/or data symbol rate of the transmitted signal from externalsystem 50. In some embodiments, the transmitted signal comprises a powersignal, and a clock and/or data is recovered without synchronizing tothe power signal. In some embodiments, the transmitted signal comprisesa clock and/or data signal, and a clock and/or data is recovered withoutsynchronizing to the transmitted clock and/or data signal. In someembodiments, the recovered signal comprises a clock and/or data and aclock and/or data is recovered from the transmission signal withoutsynchronizing to the recovered clock and/or data. Avoidingsynchronization reduces power consumption of each implantable device200, such as by obviating the need for (and avoiding the power consumedby) a frequency locked loop (FLL); phase locked loop (PLL); highfrequency clock; and/or crystal oscillator needed to perform thesynchronization. Avoiding these components can also be correlated toreduced package size of each implantable device 200 (e.g. avoidance of arelatively large sized crystal oscillator). Asynchronous data transferbetween external system 50 and implantable system 20 is alsoadvantageous as it relates to: increased communication data rate; powertransfer efficiency; operation with more than one implantable device200; and combinations of one or more of these. In some embodiments, oneor more components of apparatus 10 are of similar construction andarrangement as similar components described in U.S. patent applicationSer. No. 13/591,188, titled “Method of Making and Using an Apparatus fora Locomotive Micro-Implant using Active Electromagnetic Propulsion”,filed Aug. 21, 2012. In some embodiments, external system 50 andimplantable system 20 provide asynchronous data transfer or areotherwise configured as described in U.S. patent application Ser. No.13/734,772, titled “Method and Apparatus for Efficient Communicationwith Implantable Devices”, filed Jan. 4, 2013.

Apparatus 10 can be configured to treat pain, such as back pain and/orlimb pain treated by stimulating dorsal root ganglia and/or other nervesor locations of the spinal cord or other nervous system locations. Insome embodiments, apparatus 10 is configured to treat a type of painselected from the group consisting of: back pain; joint pain;neuropathic pain; tennis elbow; muscle pain; shoulder pain; chronic,intractable pain of the back and/or limbs including unilateral orbilateral pain; neuropathic groin pain; perineal pain; phantom limbpain; complex regional pain syndrome; failed back surgery syndrome;cluster headaches; migraines; inflammatory pain; arthritis; abdominalpain; pelvic pain; and combinations of one or more of these.

In some embodiments, apparatus 10 is configured to treat a patientdisease or disorder selected from the group consisting of: chronic pain;acute pain; migraine; cluster headaches; urge incontinence; pelvicdysfunction such as overactive bladder; fecal incontinence; boweldisorders; tremor; obsessive compulsive disorder; depression; epilepsy;inflammation; tinnitus; hypertension; heart failure; carpal tunnelsyndrome; sleep apnea; obstructive sleep apnea; dystonia; interstitialcystitis; gastroparesis; obesity; mobility issues; arrhythmia;rheumatoid arthritis; dementia; Alzheimer's disease; eating disorder;addiction; traumatic brain injury; chronic angina; congestive heartfailure; muscle atrophy; inadequate bone growth; post-laminectomy pain;liver disease; Crohn's disease; irritable bowel syndrome; erectiledysfunction; kidney disease; and combinations of one or more of these.

In some embodiments, apparatus 10 is configured to treat one or morediseases or disorders by delivering stimulation to perform renalmodulation. In some embodiments, apparatus 10 is configured to treathypertension, such as when apparatus 10 is configured to deliverstimulation to perform renal neuromodulation.

Apparatus 10 can be configured to treat heart disease, such as heartfailure of a patient. In these embodiments, stimulation of the spinalcord can be performed. In canine and porcine animals with failinghearts, spinal cord stimulation has been shown to reverse leftventricular dilation and improve cardiac function, while suppressing theprevalence of cardiac arrhythmias. In canines, coronary artery occlusionhas been associated with increased intracardiac nerve firing, andstimulation at spinal segment T1 has been shown to suppress that nervefiring. Stimulation via apparatus 10 at one or more spinal cordlocations can be used to suppress undesired cardiac nerve firing inhumans and other mammalian patients. In some embodiments, stimulationvia apparatus 10 at multiple spinal cord locations is used to enhance acardiac treatment. For example, one or more stimulation elements 260 ofone or more implantable devices 200 can be implanted at one or morespinal cord locations, such as to deliver stimulation to tissueproximate those locations. In some embodiments, stimulation elements 260comprise two or more stimulation elements (e.g. electrodes) that spanmultiple vertebra of the spinal column (e.g. multiple stimulationelements that span at least T8 to T9 and/or T-9 to T-10). Power and/ordata can be transmitted to the one or more implantable devices 200 viaone or more external devices 500 of external system 50. One or morestimulation signals can be delivered to spinal cord tissue, such as totreat heart failure or other cardiac disease or disorder. In someembodiments, one or more stimulation elements 260 are configured todeliver energy (e.g. electrical energy) to tissue to treat heartfailure, such as tissue selected from the group consisting of: spinalcanal; nerves in the spinal canal; nerves in the epidural space;peripheral nerves; posterior spinal nerve root; dorsal root; dorsal rootganglion; pre-ganglionic tissue on posterior spinal nerve root;post-ganglionic tissue on posterior nerve root; dorsal ramus; grey ramuscommunicans; white ramus communicans; ventral ramus; and combinations ofone or more of these. In some embodiments, one or more functionalelements of apparatus 10 (e.g. one or more stimulation elements 260,functional elements 299, functional elements 599 and/or other functionalelements of implantable system 20) are configured (e.g. furtherconfigured) to record a patient parameter (e.g. stimulation element 260,functional element 299, functional element 599, and/or anotherfunctional element of apparatus 10 are configured as a sensor), such asa patient heart or spine parameter, and the information recorded is usedto adjust the delivered stimulation signals. The at least one heartparameter can comprise a parameter selected from the group consistingof: EKG; blood oxygen; blood pressure; heart rate; ejection fraction;wedge pressure; cardiac output; and combinations of one or more ofthese.

Apparatus 10 can be configured to pace and/or defibrillate the heart ofa patient. One or more stimulation elements 260 can be positionedproximate cardiac tissue and deliver a stimulation signal as describedherein (e.g. based on power and/or data received by implantable system20 from external system 50). The stimulation signal can be used to pace,defibrillate and/or otherwise stimulate the heart. Alternatively oradditionally, apparatus 10 can be configured to record cardiac activity(e.g. by recording EKG, blood oxygen, blood pressure, heart rate,ejection fraction, wedge pressure, cardiac output, lung impedance and/orother properties or functions of the cardiovascular system via asensor-based element 260, and/or other sensor of apparatus 10), such asto determine an onset of cardiac activity dysfunction or other undesiredcardiac state. In some embodiments, apparatus 10 is configured to bothrecord cardiac or other information and deliver a stimulation signal tocardiac tissue (e.g. stimulation varied or otherwise based on therecorded information). For example, apparatus 10 can be configured suchthat external system 50 transmits power and/or data to implantablesystem 20. Implantable system 20 monitors cardiac activity, and upondetection of an undesired cardiovascular state, implantable system 20delivers a pacing and/or defibrillation signal to the tissue that isadjacent to one or more stimulation elements 260 configured to deliver acardiac stimulation signal.

Apparatus 10 can be configured to perform a diagnostic procedureincluding measuring one or more patient parameters (e.g. patientphysiologic or other patient parameters), such as are described indetail herebelow. In some embodiments, apparatus 10 is configured tomeasure a physiologic parameter that can be sensed from one or moresensor-based stimulation elements 260, functional elements 299, and/orfunctional elements 599 positioned in subcutaneous tissue. In theseembodiments, external system 50 can comprise an external device 500configured for placement proximate an implantable device 200 implantedin a position to record data from subcutaneous tissue (e.g. bloodglucose data). External device 500 can comprise a wrist band, awristwatch, and/or an arm band configuration such as when theimplantable device 200 is positioned in subcutaneous tissue proximatethe patient's wrist or upper arm. The external device 500 can comprise aleg, knee or ankle band configuration, such as when one or moreimplantable devices 200 are positioned in subcutaneous tissue proximatethe patient's ankle, knee, and/or thigh. In some embodiments, externaldevice 500 comprises a band or other attachment device for positioningabout the thorax, neck, groin, and/or head of the patient. Power and/ordata can be sent to the implantable device 200 from the external device500, and data (e.g. blood glucose data) can be sent to external device500 (or another component of external system 50) by implantable device200, such as using a wireless communication configuration known to thoseof skill in the art. In some embodiments, external system 50 comprises afunctional element 599 (e.g. functional element 599 a, 599 b, and/or 599c) configured to deliver an agent (e.g. insulin or glucose delivered bya needle-based functional element 599), based on the informationreceived from implantable device 200. Alternatively, or additionally,implantable device 200 comprises a stimulation element 260 configured todeliver an agent (e.g. insulin or glucose delivered by a needle-basedstimulation element 260), based on the information recorded byimplantable device 200. Various closed loop sensing and agent deliverycombinations and configurations should be considered within the spiritand scope of the present inventive concepts, including but not limitedto: sensing a blood parameter such as white blood cell count anddelivering a chemotherapeutic or other agent based on the bloodparameter; sensing a hormone level and delivering a hormone or a hormoneaffecting agent; sensing blood pressure and delivering stimulationenergy and/or a blood pressure affecting agent; sensing neural activityand delivering stimulation energy and/or a neural affecting agent orother agent based on the neural activity, such as for treating epilepsy;and combinations of one or more of these.

As described hereabove, external system 50 can be configured to transmitpower and/or data (e.g. implantable system 20 configuration data) to oneor more implantable devices 200 of implantable system 20. Implantablesystem 20 configuration data provided by external system 50 (e.g. viaone or more antennas, antenna 540 shown, of one or more external devices500) can include when to initiate stimulation delivery (e.g. energydelivery), and/or when to stop stimulation delivery, and/or it caninclude data related to the value or change to a value of one or morestimulation variables as described hereabove. The configuration data caninclude a stimulation parameter such as an agent (e.g. a pharmaceuticalagent) delivery stimulation parameter selected from the group consistingof: initiation of agent delivery; cessation of agent delivery; amount ofagent to be delivered; volume of agent to be delivered; rate of agentdelivery; duration of agent delivery; time of agent delivery initiation;and combinations of one or more of these. The configuration data caninclude a sensing parameter, such as a sensing parameter selected fromthe group consisting of: initiation of sensor recording; cessation ofsensor recording; frequency of sensor recording; resolution of sensorrecording; thresholds of sensor recording; sampling frequency of sensorrecording; dynamic range of sensor recording; initiation of calibrationof sensor recording; and combinations of one or more of these.

As described hereabove, external system 50 can comprise one or moreexternal devices 500. External system 50 can comprise one or moreantennas 540, such as when a single external device 500 comprises one ormore antennas 540, and/or when multiple external devices 500 eachcomprise one or more antennas 540. The one or more antennas 540 cantransmit power and/or data to one or more antennas 240 of implantablesystem 20, such as when a single implantable device 200 comprises one ormore antennas 240, and/or when multiple implantable devices 200 eachcomprise one or more antennas 240. In some embodiments, one or moreantennas 540 define a radiation footprint (e.g. a footprint defining avolume, such as a volume of tissue, in which electromagnetictransmissions radiated by antennas 540 can be properly received byantennas 240), such as is described in applicant's co-pending U.S.patent application Ser. No. 15/664,231, titled “Medical ApparatusIncluding an Implantable System and an External System”, filed Jul. 31,2017 [Docket nos. 47476-706.301; NAL-011-US].

External system 50 transmits power and/or data with a transmissionsignal comprising at least one wavelength, λ. External system 50 and/orimplantable system 20 can be configured such that the distance betweenan external antenna 540 transmitting the power and/or data and one ormore implantable antennas 240 receiving the power and/or datatransmission signal is equal to between 0.1λ, and 10.0λ, such as between0.2λ and 2.0λ. In some embodiments, one or more transmission signals aredelivered by a transmitter, transmitter 530, at a frequency rangebetween 10 MHz and 10.6 GHz, such as between 0.1 GHz and 10.6 GHz,between 10 MHz and 3.0 GHz, between 40 MHz and 1.5 GHz, between 10 MHzand 100 MHz, between 0.902 GHz and 0.928 GHz, in a frequency rangeproximate to 40.68 MHz, in a frequency range proximate to 866 MHz, orapproximately between 863 MHz and 870 MHz. Transmitter 530 can comprisea transmitter that produces a transmission signal with a power levelbetween 0.01 W and 4.0 W, such as a transmission signal with a powerlevel between 0.01 W and 2.0 W or between 0.2 W and 1.0 W.

In addition to transmitting power and/or data to implantable system 20,external system 50 can be further configured to provide information(e.g. patient information and/or apparatus 10 performance information)to one or more other components of apparatus 10, such as tool 60 shownin FIG. 1 and described in detail herebelow.

One or more external devices 500 (singly or collectively external device500) can be configured to transmit power and/or data (e.g. implantablesystem 20 configuration data) to one or more implantable devices 200(singly or collectively implantable device 200). In some embodiments,one or more external devices 500 are configured to transmit both powerand data (e.g. simultaneously and/or sequentially) to one or moreimplantable devices 200. In some embodiments, one or more externaldevices 500 are further configured to receive data from one or moreimplantable devices 200 (e.g. via data transmitted by one or moreantennas 240 of one or more implantable devices 200). Each externaldevice 500 can comprise housing 510, power supply 570, a transmitter530, a controller 550, and/or one or more antennas 540, each shown inFIG. 1 and described in detail herebelow. Each external device 500 canfurther comprise one or more functional elements 599 a, such as afunctional element comprising a sensor, electrode, energy deliveryelement, a magnetic-field-generating transducer, and/or any transducer,also described in detail herebelow. In some embodiments, a functionalelement 599 a comprises one or more sensors configured to monitorperformance of external device 500 (e.g. to monitor voltage of powersupply 570, quality of transmission of power and/or data to implantablesystem 20, temperature of a portion of an external device 500, and thelike).

One or more housings 510 (singly or collectively housing 510) of eachexternal device 500 can comprise one or more rigid and/or flexiblematerials which surround various components of external device 500 suchas antenna 540, transmitter 530, controller 550, and/or power supply 570shown in FIG. 1. In some embodiments, a single external device 500comprises multiple discrete (i.e. separate) housings 510, two or more ofwhich can each transfer data and/or other signals via a wired orwireless connection to the other, to an implantable device 200, and/orto another component of apparatus 10. In some embodiments, a housing 510further surrounds a programmer 600 (e.g. programmer 600′ or 600″) and/ora power supply 570. In some embodiments, housing 510 comprises both arigid material and a flexible material. In some embodiments, housing 510comprises a material selected from the group consisting of: plastic;injection-molded plastic; an elastomer; metal; and combinations of oneor more of these. In some embodiments, housing 510 comprises a shieldedportion (e.g. shielded to prevent transmission of electromagneticwaves), and an unshielded portion, such as an unshielded portionsurrounding antenna 540.

Housing 510 can comprise an adhesive element (e.g. a spacer 511configured as an adhesive element), such as an adhesive elementconfigured to temporarily attach an external device 500 to the patient'sskin. Alternatively or additionally, housing 510 can be constructed andarranged to engage (e.g. fit in the pocket of) a patient attachmentdevice, such as patient attachment device 70 described herebelow.

One or more antennas 540 (singly or collectively antenna 540) can eachcomprise one, two, three, or more external antennas. Antenna 540 cancomprise one or more polarizable antennas, such as one or more antennaswith adjustable polarization. Antenna 540 can comprise an array ofantennas, such as an array of antennas configured to: support beamshaping and/or focusing; allow adjustment of the amplitude and/or phaseof the transmission signal; increase the radiation footprint; andcombinations of one or more of these. An array of antennas 540 can beconfigured to be selectively activated, such as to improve coupling withone or more implanted antennas 240, such as to adjust for movement ofthe array of the antennas 540 relative to the implanted antennas 240.Antenna 540 can comprise an array of selectable conductors configured toadjust a radiation pattern and/or an electromagnetic field of aresultant antenna. Antenna 540 can comprise a surface and shieldmaterial positioned on the surface, such as when the shield material ispositioned on the side facing away from the patient's skin. The shieldmaterial can comprise radio-absorptive shield material and/orradio-reflective shield material. For antenna 540 to operate effectivelyat higher frequencies, the shield material can comprise a ferritematerial that has a low conductivity and low magnetic loss tangent at afrequency of interest, and whereby a higher permeability is achieved. Byplacing a material with a high magnetic permeability (μ′), low magneticloss tangent (μ″/μ′), and low conductivity at the operating frequency(such as a high frequency ferrite) between the antenna and otherelements of the transmitter, the losses or loading effects due to theseelements can be dramatically reduced. In some cases, the magnetic fieldmagnification of this shielding layer will enhance the overallperformance. Additionally, this layer shields the outside environmentfrom unwanted radiation from the antenna, and it protects the antennafrom radiation originating in the environment.

In some embodiments, a spacing layer is positioned between antenna 540and the shield material. The spacing layer can comprise a thickness ofbetween 0 mm and 5 mm, such as between 0.25 mm and 1 mm. The spacinglayer can comprise non-conductive dielectric materials, air, or othermaterials that have minimal impact on antenna performance. The spacinglayer can also be incorporated into a board thickness, with the antennabeing constructed on the opposite side of the board in relation to theshielding layer. The shielding layer can comprise a ferrite material asdescribed hereabove, or any material with the desired permeability,magnetic loss, and conductivity at the frequency of interest. Thethickness of the shielding layer can be dependent on its specificmaterial properties and the application. In some embodiments, aconductive layer on the side of the shielding layer is positionedopposite the antenna to further shield unwanted radiation. To reduceweight, the shielding layer material can be porous or incorporate holesor slots spaced in a way to minimize the reduction in performance. Theholes and spacings can be sized smaller than a wavelength of the RFsignal. If no spacing layer is used, the shielding layer can extendinside the antenna. Additionally or alternatively, the shielding layercan be positioned on the other side or both sides of the antenna becauseof the field magnification effect. In some embodiments, the shieldinglayer is constructed to increase the directivity of the antenna or focusthe electromagnetic energy.

One or more antennas 540 can be positioned in a housing 510 that isotherwise void of other components (e.g. void of power supply 570,controller 550 and/or transmitter 530), such as when an antenna 540 ispositioned within a first housing 510 and communicates with componentspositioned in a second housing 510.

In some embodiments, one or more spacers, spacer 511 shown, ispositioned between antenna 540 and the patient's skin, such as a spacercomprising a thickened portion of housing 510 or a discrete spacer 511placed on a side of housing 510 (as shown) or on a side of antenna 540.Spacer 511 can comprise one or more materials that match the impedanceof antenna 540 to the impedance of the patient's tissue. Spacer 511 cancomprise a thickness of between 0.1 cm to 3 cm, such as a thicknessbetween 0.2 cm and 1.5 cm. Spacer 511 can comprise materials whichisolate heat (e.g. a spacer 511 comprising thermally insulatingmaterial). Alternatively, or additionally, housing 510 can comprise aheat insulating and/or dissipating material. Spacer 511 can comprise asoft or otherwise compressible material (e.g. foam) for patient comfort.Spacer 511 can be inflatable, such as to control the separation distanceof an external antenna 540 from the patient's skin. An inflatable spacer511 can be compartmentalized into several sections with independentlycontrolled air pressure or volume to adjust the separation distance ofan external antenna 540 and the patient's skin and/or its angle (e.g.tilt) with respect to the tissue surface.

In some embodiments, antenna 540 comprises a multi-feed point antenna,such as a multi-feed point antenna configured to: support beam shapingand/or focusing; allow adjustment of amplitude and/or phase of atransmission signal; increase the radiation footprint; or combinationsof one or more of these.

In some embodiments, antenna 540 comprises one or more antennas selectedfrom the group consisting of: patch antenna; slot antenna; array ofantennas; a loop antenna (e.g. a concentric loop antenna); antennaloaded with reactive elements; dipole antenna; polarizable antenna;selectable conductors that form an antenna; and combinations of one ormore of these.

Antenna 540 can comprise a major axis between lcm and 10 cm, such as amajor axis between 2 cm and 5 cm, and/or a major axis of approximately 4cm. Antenna 540 can be further configured to receive a signal, such aswhen an antenna 240 is configured to transmit data to an external device500. Antenna 540 can be positioned on (e.g. fabricated onto) asubstrate, such as a flexible printed circuit board or other printedcircuit board (e.g. a single or multiple layer printed circuit boardcomprising electrical traces connecting components).

A single external antenna 540 can be configured to transmit power and/ordata to multiple implantable devices 200 (e.g. each containing one ormore antennas 240). In some embodiments, a single external device 500,comprising one or more antennas 540 can be configured to transmit powerand/or data to multiple implantable devices 200.

One or more antennas 540 can comprise a multi-turn spiral loop antenna,such as a multi-turn spiral loop antenna configured to desensitizecoupling sensitivity and/or boost input voltage. In some embodiments,one or more antennas 540 comprise multiple concentric loops with varieddimensions, such as concentric loops configured to desensitize couplingsensitivity. In these embodiments, the multiple concentric loops can be:connected in parallel and driven from the same feed point; driven fromthe same feed point and connected using one or more of a capacitor,inductor, varactor, and combinations of one or more of these; and/ordriven from multiple feed points.

In some embodiments, one or more external devices 500 comprise a firstantenna 540 and a second antenna 540. In these embodiments, the firstantenna 540 can be similar or dissimilar to the second antenna 540. Insome embodiments, a first antenna 540 and a dissimilar second antenna540 are positioned within a single external device 500 (e.g. withinhousing 510). In other embodiments, a first antenna 540 is positioned ina first external device 500, and a dissimilar second antenna 540 ispositioned in a second external device 500. The similarity ordissimilarity of the antennas can be configured to enhance one or moredesign and/or performance parameters selected from the group consistingof: implantable device 200 operation depth; polarization; powerefficiency; a radiation footprint; directional gain; beam shaping and/orfocusing; sensitivity to implantable device 200 placement; patientcomfort; patient usability; data transfer; and combinations of one ormore of these. In some embodiments, the first antenna 540 is optimizedfor a different design parameter than the second antenna 540, and eachantenna 540 can be activated independently or simultaneously to realizeboth benefits. In some embodiments, the first antenna 540 is similar tothe second antenna 540 and placed in an array to increase the radiationfootprint or placed in different external locations to operate withmultiple implantable devices 200 implanted at different sites.

In some embodiments, a first external antenna 540 and a second externalantenna 540 transmit power and/or data to a single implantable antenna240. In some embodiments, a first antenna 540 and a second antenna 540transmit power and/or data to one or more antennas 240, thetransmissions performed simultaneously or sequentially. In sequentialpower and/or data transfers, a first external device 500 comprising afirst one or more antennas 540 can be replaced (e.g. swapped) with asecond external device 500 comprising a second one or more antennas 540.Alternatively or additionally, sequential power and/or data transfer canbe initiated by one or more of the following conditions: when a firstexternal antenna 540 moves (e.g. moves relative to an implanted antenna240); when a second external device 500 comprising a second antenna 540is turned on or otherwise activated; when a second antenna 540 providesimproved power and/or data transfer to antenna 240 than that which isprovided by a first antenna 540; and/or when power received from a firstantenna 540 decreases (e.g. decreases below a threshold). In someembodiments, an antenna 240 receives power from a first antenna 540 anda second antenna 540, but only receives data from the first antenna 540.In some embodiments, a first antenna (e.g. an antenna 240 or an antenna540) is driven with a different carrier signal than a second antenna(e.g. an antenna 240 or an antenna 540). The two carrier signals cancomprise differences in amplitudes and/or relative phases as compared toeach other. Each carrier signal can include a data transmission signal(e.g. data to be transmitted to an implantable device 200 from anexternal device 500 or to an external device 500 from an implantabledevice 200).

External device 500 can comprise an electronics module, controller 550shown, configured to control one or more other components of externaldevice 500.

One or more transmitters 530 (singly or collectively externaltransmitter 530) can each comprise one or more external transmittersthat drive one or more antennas 540 (e.g. one or more antennas 540positioned in a single external device 500 or multiple external devices500). Transmitter 530 is operably attached to antenna 540 and isconfigured to provide one or more drive signals to antenna 540, such asone or more power signals and/or data signals transmitted to one or moreimplantable devices 200 of implantable system 20. Transmitter 530 can beconfigured to perform multi-level amplitude shift keying. The amplitudeshift-keying can be configured to provide adjustable-depth modulationbetween 0-100% depth, such as between 5-75% depth, or such as between10-50% depth.

As described herein, one or more external devices 500 can be configuredto transmit data (e.g. configuration data) to one or more implantabledevices 200, such as via a data transmission produced by transmitter 530and sent to one or more antennas 540. In some embodiments, a transmitter530 is configured to perform data modulation comprising amplitude shiftkeying with pulse width modulation. In these embodiments, thetransmitter can be configured to perform multi-level amplitude shiftkeying. The amplitude shift-keying can be configured to provideadjustable-depth modulation between 0-100% depth, such as between 5-75%depth, or such as between 10-50% depth. In some embodiments, one or moreexternal devices 500 transmit data to one or more implantable devices200 using time division multiple access (TDMA). In some embodiments, oneor implantable devices 200 are independently addressable through uniqueidentification (ID) codes. Alternatively or additionally, transmitter530 can be configured to transmit one or more data signals with abandwidth between 1 kHz and 100 MHz, between 0.1 MHz and 100 MHz, orbetween 1 MHz and 26 MHz.

As described herein, one or more external devices 500 can be configuredto transmit power to one or more implantable devices 200, such as via apower transmission produced by transmitter 530 and set to one or moreantennas 540. One or more transmitters 530 can deliver power to one ormore implantable devices 200 simultaneously or sequentially. In someembodiments, one or more transmitters 530 are configured to adjust thelevel of power transmitted to one or more implantable devices 200, suchas by adjusting one or more duty cycling parameters. In theseembodiments, power transmitted can be adjusted to: set a power transferbased on a stimulation level produced by implantable system 20; preventoversaturation; to reduce interference with implantable system 20 datatransmissions (e.g. when one or more implantable devices 200 are furtherconfigured to transmit data to external system 50); set a power transferbased on charge information and/or discharge information related to animplantable device 200 (e.g. charge rate and/or discharge rate ofimplantable energy storage assembly 270 described herebelow); andcombinations of one or more of these. In some embodiments, implantablesystem 20 comprises a first receiver 230 (e.g. of a first implantabledevice 200) and a second receiver 230 (e.g. of a second implantabledevice 200′). One or more transmitters 530 can be configured to transmita first power transmission to the first receiver 230, and a second powertransmission to the second receiver 230. The first power transmissionand the second power transmission can be adjusted or otherwise bedifferent, such as to prevent oversaturation.

In some embodiments, transmitter 530 (and/or another component ofexternal system 50) is further configured as a receiver (e.g. canfurther include a receiver, in addition to a transmitter or include atransmitter that further functions as a receiver), such as to receivedata from implantable system 20. For example, a transmitter 530 can beconfigured to receive data via one or more antennas 240 of one or moreimplantable devices 200. Data received can include patient information(e.g. patient physiologic information, patient environment informationor other patient information) and/or information related to animplantable system 20 parameter (e.g. an implantable device 200stimulation parameter and/or other configuration parameter as describedherein).

In some embodiments, transmitter 530 comprises a first transmitter totransmit power and/or data to one or more implantable devices 200, and asecond transmitter to transmit data to a different device, as describedherein. In these embodiments, a second transmitter of transmitter 530can be configured to transmit data to tool 60 or another device such asa programmer 600; cell phone; computer; tablet; computer network such asthe internet or a LAN; and combinations of one or more of these. In someembodiments, the second transmitter of transmitter 530 comprises awireless transmitter; a Bluetooth transmitter; a cellular transmitter;and combinations of one or more of these. In some embodiments, afunctional element 599 comprises a transmitter such as a Bluetoothtransmitter.

Each power supply 570 (singly or collectively power supply 570) can beoperably attached to a transmitter 530, and one or more other electricalcomponents of each external device 500. Power supply 570 can comprise apower supplying and/or energy storage element selected from the groupconsisting of: battery; replaceable battery (e.g. via a battery door ofhousing 510); rechargeable battery; AC power converter; capacitor; andcombinations of one or more of these. In some embodiments, power supply570 comprises two or more batteries, such as two or more rechargeablebatteries, such as to allow the first battery to be replaced (e.g.serially replaced) by the second battery (e.g. external device 500 canfunction with a single battery). In some embodiments, power supply 570is configured to provide a voltage of at least 3V. In some embodiments,power supply 570 is configured to provide a capacity between 1 Watt-hourand 75 Watt-hours, such as a battery or capacitor with a capacity ofapproximately 5 Watt-hours. In some embodiments, power supply 570comprises an AC power source. Power supply 570 can include voltageand/or current control circuitry. Alternatively or additionally, powersupply 570 can include charging circuitry, such as circuitry configuredto interface a rechargeable battery with an external charging device. Insome embodiments, apparatus 10 includes one or more charging devices,charger 61 shown, which can be configured to recharge a component ofapparatus 10, such as to recharge power supply 570 of one or moreexternal devices 500, such as is described herebelow in reference toFIGS. 17A-D.

Each external device 500 can include one or more user interfacecomponents, user interface 580 shown, such as to allow the patient orother user to adjust one or more parameters of apparatus 10. Userinterface 580 can include one or more user input components (e.g.buttons, slides, knobs, and the like) and/or one or more user outputcomponents (e.g. lights, displays and the like). In some embodiments,user interface 580 includes one or more controls configured to provide awater-ingress-resistant barrier, such as controls 581 describedherebelow in reference to FIG. 3A-D.

Each patient programmer 600′ or clinician programmer 600″ (singly orcollectively programmer 600) comprises a programming device configuredto control one or more components of apparatus 10. Programmer 600 cancomprise a user interface 680. Programmer 600 can send and/or receivecommands to and/or from one or more external devices 500 via a wirelessor wired connection (wired connection not shown but such as one or moreinsulated conductive wires). In some embodiments, one or more externaldevices 500 comprise all or a portion of programmer 600, such as whenall or a portion of user interface 680 is integrated into housing 510 ofexternal device 500. In some embodiments, apparatus 10 comprisesmultiple programmers 600, such as one or more patient programmers 600′and/or one or more clinician programmers 600″.

Programmer 600 can be configured to adjust one or more parameters ofapparatus 10, such as a stimulation parameter (e.g. a stimulationwaveform parameter as described herein); a sensing parameter; a therapyparameter; a data recording parameter (e.g. a patient data recordingparameter and/or an implantable device 200 data recording parameter);power transfer; data rate; activity of one or more external transmitters530; activity of one or more external antennas 540; a stimulationelement 260 parameter; a functional element 299 and/or 599 parameter;and combinations of one or more of these, such as is describedhereabove. Programmer 600 can be further configured to provideinformation, such as patient physiologic information recorded byapparatus 10 (e.g. by one or more implantable devices 200 and/or one ormore external devices 500), or apparatus 10 information, such asperformance and/or configuration information (singly or collectively“status information”) of one or more components of apparatus 10 (e.g.one or more external devices 500 and/or implantable devices 200). Insome embodiments, programmer 600 uses information recorded by one ormore implantable devices 200, apparatus 10 information, and/orinformation from external devices 500 to adapt configuration parametersof one or more components of apparatus 10.

In some embodiments, programmer 600 is configured to confirm that anadequate power transmission and/or an adequate data transmission hasoccurred between one or more external devices 500 and one or moreimplantable devices 200. In these embodiments, programmer 600 cancomprise diagnostic assembly 62 described herebelow, or otherwise beconfigured to detect one or more of: power transmission to theimplantable system 20 (e.g. to detect power transmission to implantablesystem 20 below a threshold); power transmission to the implantablesystem 20 trending in an undesired direction; improper and/or inadequatedata transfer to the implantable system 20; and combinations of one ormore of these. In some embodiments, programmer 600 monitors powertransfer in real time and adjusts power transmission accordingly tooptimize the rectifier efficiency (e.g. efficiency of rectifier 232described herebelow) of one or more implantable devices 200. In someembodiments, apparatus 10 can be configured to adjust (e.g. in realtime) the power transmission from one or more external devices 500 ofexternal system 50 to one or more implantable devices 200 of implantablesystem 20, such as to optimize or otherwise improve an efficiency ofapparatus 10, such as to improve the efficiency of transmissions betweenan external device 500 and an implantable device 200. These adjustmentscan include adjustment to one or more of: power transmission amplitude,duty cycle, frequency, phase, and periodicity.

In some embodiments, programmer 600 and/or another component ofapparatus 10 comprises a matching network configured to match theimpedance of one or more antennas 540 to one or more transmitters 530.The matching network can comprise an adjustable matching network. Thematching network can comprise a directional coupler configured tomeasure a reflection coefficient. A transmitter 530 can comprise anoutput, and a programmer 600 can be configured to monitor a standingwave pattern at the output of the transmitter 530.

In some embodiments, programmer 600 comprises a lookup table ofstimulation signal waveform patterns, such as to allow a clinician,patient and/or other operator of apparatus 10 to view and/or select apredetermined stimulation pattern (e.g. using user interface 680). Insome embodiments, programmer 600 comprises a set of adjustablestimulation signal parameters configured to be varied to allow anoperator to construct customized waveforms, such as to vary one or morestimulation parameters described hereabove. In some embodiments,programmer 600 is configured to allow an operator to create a customizedwaveform by specifying an amplitude of one or more discrete pulses orsteps of a stimulation signal. In some embodiments, a clinicianprogrammer 600″ can include stimulation waveform customization optionsnot provided by a patient programmer 600′.

In some embodiments, programmer 600 comprises a transmitter configuredto transmit data to tool 60 or another device such as a cell phone;computer; tablet; computer network such as the internet or a LAN; andcombinations of one or more of these. In these embodiments, programmer600 can comprise a wireless transmitter; a Bluetooth transmitter; acellular transmitter; and combinations of one or more of these. In someembodiments, programmer 600 comprises a receiver configured to receivedata, or a transceiver configured to both transmit and receive data.

User interface 680 of programmer 600 can comprise one or more user inputcomponents and/or user output components, such as a component selectedfrom the group consisting of: keyboard; mouse; keypad; switch; membraneswitch; touchscreen; display; audio transducer such as a speaker orbuzzer; vibrational transducer; light such as an LED; and combinationsof one or more of these.

In some embodiments, one or more components of external system 50 and/orother external component of apparatus 10, comprises one or morefunctional elements 599, such as functional elements 599 a, 599 b,and/or 599 c, shown positioned in external device 500, programmer 600′,and in programmer 600″, respectively. Each functional element 599 cancomprise a functional element as defined hereabove (e.g. a sensor, atransducer, and/or other functional element as described herein). Insome embodiments, a functional element 599 comprises a needle, acatheter (e.g. a distal portion of a catheter), an iontophoretic elementor a porous membrane, such as an agent delivery element configured todeliver one or more agents contained (e.g. one or more agents in areservoir, such as reservoir 525 described herebelow) within an externaldevice 500 and delivered into the patient (e.g. into subcutaneoustissue, into muscle tissue and/or into a blood vessel such as a vein).

In some embodiments, the functional element 599 comprises an electrodefor sensing electrical activity and/or delivering electrical energy. Insome embodiments, apparatus 10 is configured to cause stochasticresonance, and the addition of white noise can enhance the sensitivityof nerves to be stimulated and/or boost weak signals to be recorded bythe one or more stimulation elements 260.

In some embodiments, one or more functional elements 599 comprise asensor, such as a sensor configured to record data related to a patientparameter (e.g. a patient physiologic parameter), an external system 50parameter and/or an implantable system 20 parameter. In someembodiments, operation of one or more implantable devices 200 (e.g.stimulation energy delivered by one or more implantable devices 200) isconfigured to be delivered based on the data recorded by one or moresensor-based functional elements 599, such as in a closed-loop energydelivery mode.

Functional element 599 can comprise one or more sensors configured torecord data regarding a patient parameter selected from the groupconsisting of: blood glucose; blood pressure; EKG; heart rate; cardiacoutput; oxygen level; pH level; pH of blood; pH of a bodily fluid;tissue temperature; inflammation level; bacteria level; type of bacteriapresent; gas level; blood gas level; neural activity; neural spikes;neural spike shape; action potential; local field potential (LFP); EEG;muscular activity (e.g. as measured using electromyography, EMG);electrical activity produced by skeletal muscles (e.g. as measured usingEMG); gastric volume; peristalsis rate; impedance; tissue impedance;electrode-tissue interface impedance; physical activity level; painlevel; body position; body motion; organ motion; respiration rate;respiration level; perspiration rate; sleep level; sleep cycle;digestion state; digestion level; urine production; urine flow; bowelmovement; tremor; ion concentration; chemical concentration; hormonelevel; viscosity of a bodily fluid; patient hydration level; andcombinations of one or more of these.

Functional element 599 can comprise one or more sensors configured torecord data representing a parameter of external system 50 or anycomponent of apparatus 10. Functional element 599 can comprise one ormore sensors selected from the group consisting of: an energy sensor; avoltage sensor; a current sensor; a temperature sensor (e.g. atemperature of one or more components of external device 500 orprogrammer 600); an antenna matching and/or mismatching assessmentsensor; power transfer sensor; link gain sensor; power use sensor;energy level sensor; energy charge rate sensor; energy discharge ratesensor; impedance sensor; load impedance sensor; instantaneous powerusage sensor; average power usage sensor; bit error rate sensor; signalintegrity sensor; and combinations of one or more of these. Apparatus 10can be configured to analyze (e.g. via controller 250 describedherebelow) the data recorded by functional element 599 to assess one ormore of: power transfer; link gain; power use; energy within powersupply 570; performance of power supply 570; expected life of powersupply 570; discharge rate of power supply 570; ripple or othervariations of power supply 570; matching of antennas 240 and 540;communication error rate between implantable device 200 and externaldevice 500; integrity of transmission between implantable device 200 andexternal device 500; and combinations of one or more of these.

In some embodiments, one or more functional elements 599 are positionedon a housing 510. A functional element 599 can comprise a bodyconduction sensor, such as a body conduction sensor configured to recordand/or receive data via skin conduction. A functional element 599 can beconfigured to record data associated with stimulation delivered by oneor more implantable devices 200 (e.g. record data associated withstimulation energy delivered by one or more stimulation elements 260),such as to provide closed loop or semi-closed loop stimulation. Afunctional element 599 can be configured to record temperature, such aswhen apparatus 10 is configured to deactivate or otherwise modify theperformance of an external device 500 when the recorded temperature(e.g. patient temperature and/or external device 500 temperature)exceeds a threshold.

In some embodiments, an external device 500, programmer 600′, and/orprogrammer 600″ comprises a temperature sensor, such as when functionalelements 599 a, 599 b, and/or 599 c, respectively, comprise atemperature sensor. The temperature-based functional element 599 can bepositioned proximate a portion of programmer 600, housing 510 and/or oneor more antennas 540 (e.g. to measure the temperature of one or moreportions of a programmer 600 and/or external device 500). In theseembodiments, the temperature data recorded by the functional element 599is used to adjust one or more of: matching network; stimulation level(e.g. stimulation energy delivered by one or more implantable devices200); power transmission level (e.g. level of power transmitted betweenone or more external devices 500 and one or more implantable devices200); and combinations of one or more of these. In some embodiments, thetemperature sensor-based functional element 599 is a part of a safetymechanism that deactivates programmer 600 and/or an external device 500if the recorded temperature exceeds a threshold. Alternatively oradditionally, a temperature sensor-based functional element 599 can beconfigured to measure temperature of the patient, such as when placed onhousing 510, such as to adjust energy and/or agent delivery performed byimplantable device 200 based on the recorded patient temperature.

In some embodiments, an external device 500, programmer 600′, and/orprogrammer 600″ comprise an accelerometer, vibration sensor, and/orother motion or shock sensor, such when functional elements 599 a, 599b, and/or 599 c comprise this type of sensor. In these embodiments, thefunctional elements 599 can comprise a sensor configured to produce asignal used to detect when an external device 500, programmer 600′,and/or programmer 600″ is dropped, as well as assess the forcesgenerated during the drop. Alternatively or additionally, this sensorcan be configured to produce a signal configured to detect a tap (e.g.on a housing) of the device, such that a tap gesture can be used inplace of a control (e.g. a discrete switch) on the device.

As described hereabove, implantable system 20 comprises one or moreimplantable devices 200, such as one or more implantable devices 200provided sterile or configured to be sterilized for implantation intothe patient. A first implantable device 200 can be of similar ordissimilar construction and arrangement to a second implantable device200′. Each implantable device 200 can be configured to treat a patient(e.g. treat pain of the patient) and/or record patient information, suchas by delivering energy and/or an agent to tissue and/or by recordingone or more physiologic parameters of the patient (e.g. parameters oftissue of the patient).

One or more portions of an implantable device 200 or other component ofimplantable system 20 can be configured to be visualized or contain avisualizable portion or other visualizable element, such as visualizableelement 222 shown. Visualizable element 222 can comprise a materialselected from the group consisting of: radiopaque material;ultrasonically reflective material; magnetic material; and combinationsof one or more of these. In these embodiments, each implantable device200 can be visualized (e.g. during and/or after implantation) via animaging device such as a CT, X-ray, fluoroscope, ultrasound imagerand/or MRI.

In some embodiments, implantable system 20 comprises multipleimplantable devices 200 (e.g. implantable device 200 and implantabledevice 200′ shown in FIG. 1) and implantable system 20 comprises a“multi-point ready” system, in which the operation (e.g. energydelivery, agent deliver, data recording and/or other function) of themultiple implantable devices 200 is performed simultaneously,asynchronously, and/or sequentially. The implantable devices 200 can bepart of a network including one or more external devices 500 (e.g.external device 500 and external device 500′ shown in FIG. 1) in whichthe treating of a patient and/or the recording of patient informationrelies on operation of the implantable devices 200 at one or moreimplantation sites in a synchronized, asynchronized, and/or otherwisecoordinated way. The synchronization or otherwise coordination can becontrolled by a single and/or multiple external devices 500, which canfurther be synchronized (e.g. to a single clock). Each implantabledevice 200 of implantable system 20 can receive a power signal and/or adata signal from one or more external devices 500. In some embodimentsof the multi-point ready implantable system 20, each implantable device200 comprises a unique ID, such that each implantable device 200 isindividually addressed (e.g. receive unique signals from external system50). In some embodiments, external system 50 transmits high-bandwidthsignals to implantable system 20, such that time-domain multiple accesscommunication is performed while operating in near real time. In someembodiments, implantable system 20 is configured as a multi-point readysystem such that stimulation energy delivered by implantable system 20is independent of power received by implantable system 20 from externalsystem 50.

Two implantable devices 200, or two discrete components of a singleimplantable device 200 (e.g. two components comprising or positioned indifferent housings), can be attached to each other by a connectingfilament as defined hereabove. In some embodiments, a connectingfilament comprises a user-attachable (e.g. clinician-attachable)connector on at least one end. The filament connector is configured tooperably attach to a mating connector on a component (e.g. a housing210) of an implantable device 200.

Each implantable device 200 is configured to receive power and/or data(e.g. implantable system 20 configuration data) from one or moreexternal devices 500. In some embodiments, one or more implantabledevices 200 are configured to receive both power and data (e.g.simultaneously and/or sequentially) from one or more external devices500. In some embodiments, a single external device 500 sends powerand/or data to multiple implantable devices 200. Alternatively oradditionally, a single implantable device 200 can receive power and/ordata from multiple external devices 500. In some embodiments, a firstexternal device 500 is positioned on or near the patient's skin at alocation proximate an implanted first implantable device 200, and asecond external device 500 is positioned on or near the patient's skin(generally “on” the patient's skin) at a location proximate an implantedsecond implantable device 200. In these embodiments, the first externaldevice 500 transmits data and/or power to at least the first implantabledevice 200 and the second external device 500 transmits data and/orpower to at least the second implantable device 200.

Each implantable device 200 can comprise one or more stimulationelements 260, configured to stimulate, deliver energy to, deliver anagent to, record information from and/or otherwise interface with thepatient. Alternatively or additionally, the one or more stimulationelements 260 can be configured as a sensor, such as to record patientinformation. Each implantable device 200 can comprise housing 210,receiver 230, controller 250, energy storage assembly 270 and/or one ormore antennas 240, each described in detail herein. Each stimulationelement 260 can comprise a sensor and/or any transducer, as described indetail herein. One or more stimulation elements 260 can be positioned ona lead, lead 265 shown (e.g. a flexible filament including wires orother conductors that connect each stimulation element 260 toelectronics within housing 210). Each implantable device 200 cancomprise one or more leads 265, such as two leads attached to a singlehousing 210, or a first lead 265 attached to a first housing 210 and asecond lead 265 attached to a second housing 210. Each implantabledevice 200 can comprise one or more other functional elements, such asfunctional elements 299 a and 299 b described herein. Each implantabledevice 200 can further comprise one or more anchoring or other fixationelements, anchor element 223 shown, as described in detail herebelow.

In some embodiments, one or more implantable devices 200 are furtherconfigured to transmit data to one or more external devices 500, such asvia one or more antennas 240 transmitting a signal to one or moreantennas 540, or otherwise. Data transmitted by an implantable device200 can comprise patient information (e.g. patient physiologicinformation recorded by one or more stimulation elements 260 configuredas a physiologic sensor), or implantable device 200 information (e.g.data recorded by one or more stimulation elements 260 configured as asensor and positioned in implantable device 200, or other implantabledevice 200 configuration and/or performance data).

Housing 210 of each implantable device 200 can comprise one or morerigid and/or flexible materials which surround various components, suchas antenna 240, energy storage assembly 270, controller 250 and/orreceiver 230 as shown in FIG. 1. In some embodiments, one or morestimulation elements 260 are positioned in, on and/or within housing210. In some embodiments, housing 210 surrounds a substrate, such as aflexible and/or foldable printed circuit board, such as multiplediscrete or continuous printed circuit boards positioned in differentplanes (e.g. a flexible or foldable printed circuit board). In someembodiments, one or more antennas 240 and/or other components (e.g. afunctional element 299) are positioned outside of housing 210, such aswhen at least one antenna 240 or other components is operably connectedto one or more components (e.g. electrical components) positioned withinhousing 210 via a tether comprising one or more electrical conduits.

Housing 210 can comprise one or more shapes or combination of shapes,such as one or more shapes selected from the group consisting of: disc;pill; cylinder; sphere; oblate spheroid; dish-like shape; bowl-likeshape; cone; rectangular prism; trapezoidal prism; a portion of atoroid; and combinations of one or more of these.

Housing 210 can comprise a major axis and a minor axis, definedhereabove. In some embodiments, housing 210 comprises a major axis lessthan or equal to 20 mm, such as a major axis less than or equal to 15mm, 12 mm or 10 mm. In some embodiments, housing 210 comprises a minoraxis less than or equal to 8 mm, such as a minor axis less than or equalto 6 mm, or less than or equal to 5 mm. Housing 210 can comprise a wallthickness between 0.1 mm and 1.0 mm, such as a wall thickness between0.2 mm and 0.5 mm, such as a wall thickness of approximately 0.3 mm.Housing 210 can comprise a displacement volume less than or equal to2000 mm³, such as less than or equal to 600 mm³.

Housing 210 can comprise one or more portions that are transmissive toradiofrequency (RF) signals. In some embodiments, housing 210 comprisesglass. In some embodiments, housing 210 comprises a material selectedfrom the group consisting of: glass; ceramic; stainless steel; titanium;polyurethane; an organic compound; liquid crystal polymer (LCP); gold;platinum; platinum iridium; tungsten; epoxy; a thermoplastic; athermoset plastic; and combinations of one or more of these. In someembodiments, one or more portions of housing 210 comprises one or morecoatings, such as one or more coatings configured to cause or prevent aphysiologic reaction and/or a coating configured to block (e.g. shield)an electromagnetic transmission.

Housing 210 can comprise one or more passageways or other feedthroughs,such as for the passage of a lead, wire, optical fiber, fluid deliverytube, mechanical linkage and/or other conduit through a wall of housing210, such as is described in applicant's co-pending U.S. patentapplication Ser. No. 15/664,231, titled “Medical Apparatus Including anImplantable System and an External System”, filed Jul. 31, 2017 [Docketnos. 47476-706.301; NAL-011-US].

In some embodiments, one or more inner or outer surfaces (or portions ofsurfaces) of housing 210 includes an insulating and/or shielding layer(e.g. a conductive electromagnetic shielding layer), such as innercoating 219 a and/or outer coating 219 b shown (singly or collectivelycoating 219). Coating 219 can comprise an electrically insulating and/ora thermally insulating layer or other coating. In some embodiments, oneor more portions of housing 210 comprise an electrically shieldingcoating, coating 219, while other portions are transmissive toelectromagnetic signals such as radiofrequency signals.

In some embodiments, housing 210 comprises an array of feedthroughs, notshown. In some embodiments, housing 210 is surrounded (e.g. partially orfully surrounded) by a covering, such as a flexible and/ornon-conductive covering, such as a covering made of an elastomer.

In some embodiments, implantable device 200 and/or another component ofapparatus 10 can include one or more features to prevent or at leastreduce migration of implant 200 within the patient's body. In someembodiments, one or more implantable devices 200 comprises one or moreanchor elements configured to secure one or more portions of implantabledevice 200 to tissue (e.g. anchor element 223 described hereabove and/oran anchor element in an overmold positioned about a portion of housing210). Anchor element 223 can comprise one or more anchoring elementsselected from the group consisting of: a sleeve such as a siliconesleeve; suture tab; suture eyelet; bone anchor, wire loops; porous mesh;penetrable wing; penetrable tab; bone screw eyelet; tine; pincers;suture slits; and combinations of one or more of these. While anchorelement 223 is shown proximate housing 210 (e.g. to fixedly attachhousing 210 to tissue), in some embodiments anchor element 223 surroundsor is otherwise proximate lead 265 (e.g. to fixedly attach lead 265 totissue), such as is described herebelow in reference to FIGS. 8A-C. Insome embodiments, anchor element 223 comprises a porous mesh thatsurrounds all or a portion of housing 210. The porous mesh can beconfigured to promote tissue ingrowth, such as to prevent or at leastlimit (“prevent” herein) migration of housing 210 when implantabledevice 200 is implanted in the patient. In some embodiments, anchorelement 223 comprises a mesh that is attached to the top side ofimplantable device 200 (side in closest proximity to the patient'sskin), such as to prevent housing 210 from migrating away from thepatient's skin (e.g. prevent from migrating deeper into the patient).

One or more antennas 240 (singly or collectively antenna 240) can beconfigured to receive power and/or data, and receiver 230 can receivethe power and/or data from the one or more antennas 240. Each antenna240 can comprise one or more implantable antennas, such as one or moreantennas positioned within housing 210, and/or one or more antennaselectrically attached to a connecting filament. In some embodiments, oneor more implantable devices 200 comprise at least two antennas 240, orat least three antennas 240. Antenna 240 can be configured to receivepower and/or data from one or more external devices 500, such that anattached receiver 230 receives the power and/or data. In someembodiments, implantable system 20 comprises at least two implantabledevices 200, each of which comprise one or more (e.g. two or three)antennas 240 which are positioned within a housing 210 and/orelectrically tethered to a housing 210. In some embodiments, animplantable device 200 comprises a first antenna 240 positioned in afirst plane and a second antenna 240 positioned in a second plane. Thefirst plane and second plane can be relatively orthogonal planes, orplanes oriented between 30° and 90° relative to each other, such asbetween 40° and 90°, approximately 30°, approximately 45° and/orapproximately 60° relative to each other. In some embodiments, animplantable device 200 comprises a first antenna 240 positioned in afirst plane, a second antenna 240 positioned in a second plane, and athird antenna 240 positioned in a third plane.

In some embodiments, implantable device 200 comprises one or moreantennas 240 positioned on a substrate, such as a printed circuit board(PCB), a flexible printed circuit board and/or a foldable substrate(e.g. a substrate comprising rigid portions and hinged portions). Insome embodiments, the substrate is folded or otherwise pivoted toposition the various antennas 240 on differently oriented planes, suchas multiple planes oriented between 5° and 90° relative to each other,such as two antennas 240 positioned on two planes oriented between 30°and 90° or between 40° and 90° relative to each other, or three antennas240 positioned on three planes oriented between 5° and 60° relative toeach other. Two or more antennas 240 can be positioned on two or moredifferent planes that are approximately 45° relative to each other, orapproximately 60° or approximately 90° relative to each other.

Implantable device 200 can comprise three antennas 240. In someembodiments, a first antenna 240 comprises an electrical dipole antenna,and the second and third antennas 240 can be positioned in differentplanes than the first antenna 240. In some embodiments, the threeantennas 240 each comprise a loop antenna, such as when each loopantenna is positioned on a different plane. In some embodiments, a firstantenna 240 comprises an electrical dipole antenna, and a second antenna240 and a third antenna 240 each comprise a loop antenna. In theseembodiments, the second antenna 240 and the third antenna 240 can bepositioned relatively orthogonal to each other (e.g. positioned on tworelatively orthogonal planes). In some embodiments, a first antenna(e.g. an electrical dipole antenna) is positioned outside of housing210, while a second antenna (e.g. a loop antenna) and a third antenna(e.g. a loop antenna) are each positioned on, in and/or within housing210. In some embodiments, implantable device 200 comprises one or moreantennas 240 in which any combination of antenna types (as describedherein) are used in combination.

One or more antennas 240 can comprise an antenna selected from the groupconsisting of: loop antenna; multiple-turn loop antenna; planar loopantenna; coil antenna; dipole antenna; electric dipole antenna; magneticdipole antenna; patch antenna; loaded dipole antenna; concentric loopantenna; loop antenna with ferrite core; and combinations of one or moreof these. One or more antennas 240 can comprise a loop antenna, such asan elongated loop antenna or a multiple-turn loop antenna.

One or more antennas 240 can comprise a multi-turn spiral loop antenna,such as a multi-turn spiral loop antenna configured to desensitizecoupling sensitivity and/or boost input voltage. In some embodiments,one or more antennas 240 comprise multiple concentric loops with varieddimensions, such as concentric loops configured to desensitize couplingsensitivity. In these embodiments, the multiple concentric loops can bearranged as follows: connected in parallel and driven from the same feedpoint; driven from the same feed point and connected using one or moreof a capacitor, inductor, varactor, and combinations of one or more ofthese; and/or driven from multiple feed points.

One or more antennas 240 can comprise a minor axis and a major axis. Insome embodiments, one or more antennas 240 comprise a minor axis between1 mm and 8 mm, such as between 2 mm and 5 mm. In some embodiments, oneor more antennas 240 comprise a major axis between 3 mm and 15 mm, suchas between 4 mm and 8 mm. In some embodiments, one or more antennas 240comprise a major axis above 3 mm, such as between 3 mm and 15 mm, suchas when the antenna 240 is positioned outside of housing 210.

One or more antennas 240 can comprise a foldable and/or unfoldableantenna, such as is described in applicant's co-pending U.S. patentapplication Ser. No. 14/975,358, titled “Method and Apparatus forMinimally Invasive Implantable Modulators”, filed Dec. 18, 2015 [Docketnos. 47476.703.301; NAL-005-US].

One or more antennas 240 can be positioned inside of housing 210.Alternatively or additionally, one or more antennas 240 can bepositioned outside of housing 210.

Implantable system 20, one or more implantable devices 200 and/or one ormore antennas 240 can be configured to be positioned at a desired depthbeneath the patient's skin, such as at a depth between 0.5 cm and 7.0cm, such as a depth of between 1.0 cm and 3.0 cm.

One or more energy storage assemblies 270 (singly or collectively energystorage assembly 270) can comprise one or more implantable energystorage components, such as one or more batteries (e.g. rechargeablebatteries) and/or capacitors (e.g. a supercapacitor). Energy storageassembly 270 can be configured to provide power to one or more of: oneor more stimulation elements 260; controller 250; receiver 230; andcombinations of one or more of these. In some embodiments, energystorage assembly 270 further provides power to one or more antennas 240and/or circuitry configured to transmit data via antenna 240. In someembodiments, energy storage assembly 270 includes digital control forcharge/discharge rates, voltage outputs, current outputs, and/or systempower distribution and/or management.

Energy storage assembly 270 can comprise one or more capacitors with asingle or collective capacitance between 0.01 μF and 10 F, such as acapacitance between 1 μF and 1.0 mF, or between 1 μF and 10 μF. Theenergy storage assembly 270 can comprise one or more capacitors withcapacitance between 1 mF and 10 F, such as when energy storage assembly270 comprises a super-capacitor and/or an ultra-capacitor. Such largecapacitance can be used to store sufficient charge to maintain operation(e.g. maintain delivery of stimulation energy and/or delivery of anagent) without the use (e.g. sufficient proximity) of an associatedexternal device 500. A capacitor or other energy storage element (e.g. abattery) can be chosen to provide sufficient energy to maintainoperation for at least 30 seconds, at least 2 minutes, at least 5minutes, at least 30 minutes, and up to several hours or more (e.g.during showering, swimming or other physical activity). In someembodiments, energy storage assembly 270 is configured to providecontinuous and/or intermittent stimulation energy for at least onecharge-balanced pulse (e.g. for the duration of at least onecharge-balanced pulse). In some embodiments, a capacitor, battery orother energy storage element is configured to provide stimulation energywithout receiving externally supplied power for periods of at least 1hour, at least 1 day, at least 1 month or at least 1 year. Energystorage assembly 270 can comprise one or more capacitors with abreakdown voltage above 1.0V, such as a breakdown voltage above 1.5V,4.0V, 10V, or 15V. In some embodiments, energy storage assembly 270 cancomprise capacitors distributed outside of housing 210, such as when oneor more capacitors are distributed along lead 265. Energy storageassembly 270 can comprise one or more capacitors with low self-leakage,such as to maintain stored energy for longer periods of time.

In some embodiments, energy storage assembly 270 comprises a temporaryenergy storage component, such as a super-capacitor, configured to storea sufficient quantity of energy to provide uninterrupted stimulation,such as during time periods in which the link gain may be of poorquality or it may be temporarily unavailable (e.g. an external device500 not being in place such as during a shower, swimming, and the like).An energy storage assembly 270 comprising an ultra-capacitor,super-capacitor or flexible battery can be charged via the wirelesspower transmission of the present inventive concepts, such as to store asufficient amount of energy for one or more stimulation elements 260 todeliver stimulation energy during subsequent (intended or unintended)unavailability of one or more external devices 500 (e.g. an externaldevice 500 is intentionally removed or unintentionally falls off orotherwise loses its position sufficiently proximate one or moreimplantable devices 200). An energy storage assembly 270 comprising oneor more high capacity energy storage components can be beneficial inapplications where therapy interruption provides a significant risk oris otherwise relatively unacceptable, such as for life supporttherapies, cardiac resynchronization therapies, and the like. The highcapacity energy storage components of energy storage assembly 270 can bepositioned in an assembly positioned within housing 210, on an inner orouter surface of housing 210, within a separate housing, and/or withinlead 265.

In some embodiments, during use (e.g. during period of providingstimulation or other function) implantable device 200 receives powerregularly from external system 50 (e.g. relatively continuously whileimplantable device 200 delivers stimulation energy), and energy storageassembly 270 comprises a relatively small battery or capacitor, such asa battery or capacitor that has an energy storage capacity of less thanor equal to 0.6 Joules, 7 Joules or 40 Joules.

One or more controllers 250 (singly or collectively controller 250) canbe configured to control one or more stimulation elements 260, such as astimulation element 260 comprising a stimulation-based transducer (e.g.an electrode or other energy delivery element) and/or a sensor (e.g. aphysiologic sensor and/or a sensor configured to monitor an implantabledevice 200 parameter). In some embodiments, controller 250 is configuredto transmit a stimulation signal (e.g. transmit stimulation energyconfigured in one or more stimulation waveforms) to one or morestimulation elements 260 (e.g. one or more stimulation elements 260comprising an electrode and/or other energy delivery element),independent of the power signal received by one or more antennas 240(e.g. independent of power transmitted by external system 50), such asby using energy stored in energy storage assembly 270. In theseembodiments, the power signal and/or the RF path for the power signalcan be adjusted to optimize power efficiency (e.g. by tuning matchingnetwork on transmitter 530 and/or receiver 230; configuring antennas 540and/or 240 in an array; tuning operating frequency; duty cycling thepower signal; adjusting antenna 540 and/or 240 position; and the like),and a stimulation signal can be precisely delivered (e.g. by usingenergy stored on energy storage assembly 270 and generating stimulationsignal locally on the implantable device 200) to ensure clinicalefficacy. Also, if the power signal transmission (also referred to as“power link”) is perturbed unexpectedly, the stimulation signal can beconfigured so that it is not significantly affected (e.g. unaffected).In some configurations, the stimulation signal being delivered by one ormore implantable devices 200 is insensitive to interference that may bepresent. In these embodiments, a power transmission signal andstimulation signal can vary in one or more of: amplitude; changes inamplitude; average amplitude; frequency; changes in frequency; averagefrequency; phase; changes in phase; average phase; waveform shape; pulseshape; duty cycle; polarity; and combinations of one or more of these.

Controller 250 can receive commands from receiver 230, such as one ormore commands related to one or more implantable device 200configuration parameters selected from the group consisting of:stimulation parameter; data rate of receiver; data rate of datatransmitted by the first implantable device 200 at least one implantableantenna 240; stimulation element 260 configuration; state of controller250; antenna 240 impedance; clock frequency; sensor configuration;electrode configuration; power management parameter; energy storageassembly parameter; agent delivery parameter; sensor configurationparameter; and combinations of one or more of these.

In some embodiments, one or more stimulation elements 260 comprise astimulation element configured to deliver energy (e.g. one or moreelectrodes configured to deliver monopolar or bipolar electrical energy)to tissue, and controller 250 is configured to control the energydelivery, such as to control one or more stimulation parameters. Each ofthese stimulation parameters can be held relatively constant, and/orvaried, such as a variation performed in a continuous or intermittentmanner. In some embodiments, one or more stimulation parameters arevaried in a random or pseudo-random (hereinafter “random”) manner, suchas a variation performed by apparatus 10 using a probabilitydistribution as described in applicant's co-pending U.S. patentapplication Ser. No. 16/104,829, titled “Apparatus with EnhancedStimulation Waveforms”, filed Aug. 17, 2018 [Docket nos. 47476-708.301;NAL-014-US]. In some embodiments, stimulation (e.g. stimulationcomprising high frequency and/or low frequency signal components) isvaried randomly to eliminate or at least reduce synchrony of neuronalfiring with the stimulation signal (e.g. to reduce paresthesia or otherpatient discomfort). In some embodiments, one or more stimulationelements 260 comprise a stimulation element configured to stimulate atarget (e.g. nerve tissue such as spinal nerve tissue and/or peripheralnerve tissue). The amount of stimulation delivered to the target can becontrolled by varying a parameter selected from the group consisting of:stimulation element 260 size and/or configuration (e.g. electrode sizeand/or configuration); stimulation element 260 shape (e.g. electrodeshape, magnetic field generating transducer shape or agent deliveringelement shape); shape of a generated electric field; shape of agenerated magnetic field; stimulation signal parameters; andcombinations of one or more of these.

In some embodiments, one or more stimulation elements 260 comprise anelement configured to deliver electrical energy to tissue (e.g. one ormore electrodes configured to deliver monopolar or bipolar electricalenergy), and controller 250 is configured to control charge balance,such as to actively and/or passively control charge balance, asdescribed herebelow. Charge balance can be essential for patient safetyin electrical stimulation of nerves or other tissue. Imbalancedstimulation waveforms can cause electrode corrosion and/or dissolutionwhich can lead to deposition of toxic materials in tissue, implantrejection, and nerve damage. The stimulation waveform can be balancedsuch that net outflow charge approximately equals net inflow charge.With stimulation waveform amplitudes that can vary between 0.01 mA to 15mA (such as between 0.1 mA and 15 ma, between 0.1 mA and 12 mA, orbetween 0.1 mA and 10 mA), depending on the treatment, the error incharge balance can be on the order of 0.001% to 0.01%. Alternatively oradditionally, controller 250 can comprise AC coupling capacitors thatare configured to balance stimulation waveforms passively. The ACcoupling capacitance can be fairly large (e.g. greater than 10 μF), inorder to pass the stimulation waveform with minimal filtering. In someembodiments, apparatus 10 is configured to perform active chargebalancing. In some embodiments, an implantable device 200 comprises aprecise resistor in series with a stimulation electrode-basedstimulation element 260. The precise resistor can be used to measureoutflow and inflow currents, such as when controller 250 comprises ananalog to digital converter (ADC). Controller 250 can integrate currentover time during a first phase in which stimulation energy is delivered,and during a second phase in which a reverse current is applied (e.g. areverse current used to balance charge). Controller 250 can beconfigured to balance the total charge in the two phases, to ensure thatthe net DC current is approximately zero. The integration can beachieved using an analog integrator and/or a digital summer ofcontroller 250, with controller 250 keeping track of one or moreparameters of the pulses delivered (e.g. pulses delivered within a trainor a burst). Implantable device 200 can comprise a precise seriesresistance comprising an “on-chip” trimmed resistor or an “off-chipresistor”. In some embodiments, implantable device 200 comprises a bankof trimmed resistors that are used to control the net series resistance,such as to adjust resistance based on stimulation amplitude requirements(e.g. to take advantage of the full dynamic range of an ADC ofcontroller 250). In some embodiments, controller 250 comprises a shuntpath with an RC-based low pass filter used for both outflow and inflowof current. RC elements of controller 250 can be chosen such that theshunt current is only a fraction of the stimulation current. Since thesame RC elements can be used for both outflow and inflow current, theprecision required for the RC components can be lower. An ADC can beused to sense the voltage on the capacitor at the end of a stimulationpulse. After the stimulation pulse, the capacitor can be discharged andthe polarity of the stimulation current can be reversed and set to anyamplitude, until the capacitor is charged to approximately the samevoltage (according to the ADC precision) as it was charged during thestimulation pulse. The ADC resolution can be high enough to ensure theresidual error is less than what would cause an undesired chargeaccumulation. ADC resolution requirements can be further reduced byreducing the net capacitance in a shunt RC circuit, to cause acceleratedcharging of the capacitor. The capacitor can be discharged every timethe voltage exceeds a certain predefined threshold, while controller 250keeps track of the number of times the capacitor has been charged andreset. By resetting the capacitor through a low resistance path, thedischarge time can be insignificant compared to the charge time,reducing the error due to the discharge period. Since the net chargeequivalent to full scale voltage on the ADC can be divided into multiplecycles, the required resolution of the ADC to achieve the same residualerror can be divided by the number of cycles.

In some embodiments, controller 250 is configured to produce astimulation signal comprising a waveform or a waveform pattern(hereinafter stimulation waveform), for one or more stimulation elements260 configured as a stimulation element (e.g. such that one or morestimulation elements 260 deliver stimulation energy comprising or atleast resembling that stimulation waveform). Controller 250 can producea stimulation signal comprising a waveform selected from the groupconsisting of: square wave; rectangle wave; sine wave; sawtooth;triangle wave (e.g. symmetric or asymmetric); trapezoidal; ramp;waveform with exponential increase; waveform with exponential decrease;pulse shape which minimizes power consumption; Gaussian pulse shape;pulse train; root-raised cosine; bipolar pulses; and combinations of oneor more of these. In some embodiments, controller 250 is configured toproduce a stimulation signal comprising a waveform including acombination of two or more waveforms selected from the group consistingof: square wave; rectangle wave; sine wave; triangle wave (symmetric orasymmetric); ramp; waveform with exponential increase; waveform withexponential decrease; pulse shape which minimizes power consumption;Gaussian pulse shape; pulse train; root-raised cosine; bipolar pulses;and combinations of one or more of these. In some embodiments,controller 250 is configured to construct a custom waveform (e.g. anoperator customized waveform), such as by adjusting amplitude atspecified time steps (e.g. for one or more pulses). In some embodiments,controller 250 is configured to generate a waveform including one ormore random parameters (e.g. random timing of pulses or random changesin frequency, rate of change or amplitude).

In some embodiments, controller 250 is configured to provide astimulation signal comprising waveforms and/or pulses repeated at afrequency (e.g. includes a frequency component) between 1.0 Hz and 50KHz, such as between 10 Hz and 500 Hz, between 40 Hz and 160 Hz and/orbetween 5 KHz and 15 KHz. In some embodiments, controller 250 isconfigured to produce a stimulation signal comprising a frequencybetween 1 Hz and 1000 Hz, such as a stimulation signal with a frequencybetween 10 Hz and 500 Hz. In some embodiments, controller 250 isconfigured to produce a stimulation signal comprising a duty cyclebetween 0.1% and 99%, such as a duty cycle between 1% and 10% or between1% and 25%. In some embodiments, controller 250 is configured to producea stimulation signal comprising a frequency modulated stimulationwaveform, such as a stimulation waveform comprising a frequencycomponent (e.g. signal) between 1 kHz and 20 kHz. In some embodiments,controller 250 is configured to produce a stimulation signal comprisinga mix and/or modulation of low frequency and high frequency signals,which comprise any of the waveform types, shapes and otherconfigurations. In these embodiments, the stimulation signal cancomprise low frequency signals between 1 Hz and 1000 Hz, and highfrequency signals between 600 Hz and 50 kHz, or between 1 kHz and 20kHz. Alternatively or additionally, the stimulation signal can comprisea train of high frequency signals and bursts of low frequency signals,and/or a train of low frequency signals and bursts of high frequencysignals. Alternatively or additionally, the stimulation signal cancomprise one or more high frequency signals modulated with one or morelow frequency signals, such as one or more high frequency signalsfrequency modulated (FM), amplitude modulated (AM), phase modulated (PM)and/or pulse width modulated (PWM) with one or more low frequencysignals. The stimulation signal can cycle among different waveformsshapes at specified time intervals. The stimulation signal can comprisea pseudo random binary sequence (PRBS) non-return-to-zero orreturn-to-zero waveform, such as with a fixed and/or time-varying pulsewidth and/or frequency of the pulses.

Controller 250 can comprise a clamping circuit configured to allow fastcharging and/or discharging of the energy storage assembly 270,stimulation element 260 drivers (e.g. electrode drivers) of controller250, and/or other components of implantable device 200. The clampingcircuit can improve pulse shape by offering additional control and/orconfiguration of rise and fall times in the shape of the waveform (e.g.to create rapid rise or fall times). In some embodiments, the clampingcircuit can be configured to limit the rise and/or fall time to be lessthan or equal to one-tenth (10%) of the pulse width of an appliedstimulation pulse (e.g. less than or equal to 1 μsec rise and/or falltime for a 10 μsec stimulation pulse).

In some embodiments, controller 250 comprises a matching networkconfigured to match the impedance of a first antenna 240 with theimpedance of the receiver 230. In these embodiments, controller 250'smatching network can be adjustable. Alternatively or additionally,controller 250 can comprise an adjustable loading impedance to stabilizethe load seen at an antenna 240 under different operating conditions. Insome embodiments, the adjustable loading impedance is controlledaccording to the charge rate of the energy storage assembly 270.

Controller 250 and/or any other component of each implantable device 200can comprise an integrated circuit comprising one or more componentsselected from the group consisting of: matching network; rectifier;DC-DC converter; regulator; bandgap reference; overvoltage protection;overcurrent protection; active charge balance circuit; analog to digitalconverter (ADC); digital to analog converter (DAC); current driver;voltage driver; digital controller; clock generator; data receiver; datademodulator; data modulator; data transmitter; electrode drivers;sensing interface analog front end; power management circuit; energystorage interface; memory register; timing circuit; and combinations ofone or more of these.

One or more receivers 230 (singly or collectively receiver 230) cancomprise one or more components, such as demodulator 231, rectifier 232,and/or power converter 233 shown in FIG. 1. In some embodiments,receiver 230 can comprise a DC-DC converter such as a boost converter.Receiver 230 can comprise a data receiver, such as a data receiverincluding an envelope detector and demodulator and/or an envelopeaveraging circuit. In some embodiments, one more antennas 240 separatelyconnect to one or more receivers 230. In some embodiments, one or moreantennas 240 connect to a single receiver 230, such as via a seriesconnection or a parallel connection.

One or more implantable devices 200 can be configured to transmit a datasignal to external system 50. In some embodiments, receiver 230 isconfigured to drive one or more antennas 240 to transmit data toexternal system 50 (e.g. to an antenna 540 of an external device 500).Alternatively or additionally, implantable device 200 can be configuredto transmit a data signal by having receiver 230 adjust a load impedanceto backscatter energy, such as a backscattering of energy which can bedetected by external system 50. In some embodiments, data transmissionis accomplished by receiver 230 manipulating a signal at a tissueinterface, such as to transmit a data signal using body conduction.

In some embodiments, receiver 230 comprises a matching network, such asa matching network configured to detune to prevent oversaturation. Forexample, implantable system 20 can comprise two or more implantabledevices 200 each of which includes a receiver 230 comprising a matchingnetwork. A first implantable device 200's receiver 230's matchingnetwork can be configured to detune based on power received by thesecond implantable device 200's receiver 230.

Demodulator 231 can comprise circuitry that asynchronously recoverssignals modulated on the power signal provided by external system 50,and that converts the modulated signals into digital signals. In someembodiments, demodulator 231 asynchronously recovers the modulatedsignal by comparing a dynamically generated moving average with theenvelope, outputting a high voltage when the envelope is greater thanthe moving average and a low voltage when the envelope is less than themoving average. Data can then be extracted from this resulting digitalsignal from the width and/or amplitude of the pulses in the signal,according to the encoding method used by external system 50. In someembodiments, demodulator 231 recovers a digital signal that is used astiming information for an implantable device 200, similar to an on-chipclock. The recovered clock signal can also be used to synchronize anon-chip clock generator of controller 250, such as through the use of afrequency and/or phase locked loop (FLL or PLL).

Rectifier 232 can comprise a power signal rectifier, such as to providepower to the energy storage assembly 270 and/or controller 250. In someembodiments, rectifier 232 comprises one or more self-driven synchronousrectifier (SDSR) stages connected in charge-pump configuration, to boostthe voltage from input RF amplitude to the rectifier to a highervoltage. The boosted voltage can directly charge energy storage assembly270, or it can be further boosted by a DC-DC converter or boostconverter. In some embodiments, rectifier 232 comprises diode-capacitorladder stages instead of, or in addition to, SDSR stages. On-chipdiodes, such as Schottky diodes, or off-chip diodes can be used in oneor more rectifier 232 stages. For maximum efficiency, the rectificationelements, such as diodes, can be optimized to minimize forwardconduction and/or reverse conduction losses by properly sizing thecomponents and selecting appropriate number of stages based on the inputRF voltage and load current.

Power converter 233 can comprise one or more voltage conversion elementssuch as DC-DC converters that boost or otherwise change the voltage to adesired level. In some embodiments, voltage conversion is achieved witha buck-boost converter, a boost converter, a switched capacitor, and/orcharge pumps. One or more power converters 233 can interface with energystorage assembly 270 and charge up associated energy storage componentsto desired voltages. In some embodiments, power converter 233 receivescontrol signals from controller 250, such as to configure voltages,currents, charge/discharge rates, switching frequencies, and/or otheroperating parameters of power converter 233.

One or more implantable leads 265 (singly or collectively lead 265) canbe attached to one or more housings 210, such as a lead 265 comprisingone or more stimulation elements 260. Lead 265 can comprise one or morestimulation elements 260 configured as a stimulation element (e.g. anelectrode configured to deliver electrical energy in monopolar orbipolar mode or an agent delivery element such as an output port fluidlyconnected to a reservoir within housing 210). Alternatively oradditionally, lead 265 can comprise one or more stimulation elements 260and/or functional elements 299 b that is configured as a physiologicsensor (e.g. an electrode configured to record electrical activity oftissue or another physiologic sensor as described herein). Alternativelyor additionally, lead 265 can comprise one or more stimulation elements260 and/or functional elements 299 b that is configured to transmitsignals through tissue to external system 50, such as through bodyconduction.

In some embodiments, implantable device 200 comprises a connector,connector 215, that operably attaches (e.g. electrically attaches) oneor more stimulation elements 260 to one or more components (e.g.electronic components) internal to housing 210 (e.g. to transfer powerand/or data therebetween). Connector 215 can be constructed and arrangedas described herebelow in reference to any of FIGS. 13A-C and/or 14A-B.In some embodiments, connector 215 is operably attached (e.g. in amanufacturing process) or attachable (e.g. in a clinical procedure) tolead 265 as shown in FIG. 1. Alternatively, connector 215 can beoperably attached and/or attachable to a lead connection assembly,assembly 280, which in turn can be attached to a lead 265, such as isdescribed herebelow in reference to any of FIGS. 7A-D, 13A-C, and/or14A-B. In some embodiments, connector 215 passes through an opening inhousing 210, in a feed-through arrangement. In some embodiments, anovermold or other sealing element, sealing element 205 shown, provides aseal about connector 215, the opening in housing 210 and/or theinterface between connector 215 and housing 210.

In some embodiments, lead 265 comprises a removable stylet configured toaid in the implantation of lead 265, such as is described in applicant'sco-pending U.S. patent application Ser. No. 15/664,231, titled “MedicalApparatus Including an Implantable System and an External System”, filedJul. 31, 2017 [Docket nos. 47476-706.301; NAL-011-US]. In someembodiments, implantable system 20 comprises more than one lead 265,comprising one or more stimulation elements 260 and attached to one ormore housings 210 of one or more implantable devices 200. In someembodiments, one or more leads 265 can be attached to a single housing210.

In some embodiments, lead 265 comprises a diameter between 1 mm and 4mm, such as a diameter between 1 mm and 2 mm, such as a lead with adiameter of approximately 1.35 mm. In some embodiments, lead 265comprises a length between 3 cm and 60 cm, such as a length between 6 cmand 30 cm. One or more leads 265 can include between 2-64 stimulationelements 260, such as when a lead 265 comprises between 2 and 64electrodes, such as between 4 and 32 electrodes. In some embodiments,lead 265 comprises a paddle lead. In some embodiments, lead 265comprises a single or multi-lumen catheter, such as when an attachedimplantable device 200 is configured as an agent delivery apparatus asdescribed herein (e.g. a stimulation element 260 configured as acatheter comprises at least a portion of lead 265).

In some embodiments, lead 265 comprises one or more tines, such as tines266 shown. Tines 266 can be configured to anchor or otherwise stabilize(“anchor” or “stabilize” herein) lead 265 relative to patient tissue,such as to prevent undesired movement during and/or after animplantation procedure for lead 265. One or more tines 266 can beconfigured to biodegrade after implantation in the patient, such thatthe stabilization provided is temporary. Tines 266 can be configured tobiodegrade over a time period of approximately 4 to 12 weeks. In someembodiments, biodegradable tines 266 are configured to be incorporatedwhen lead stimulation elements 260 are positioned to stimulate aperipheral nerve (e.g. lead 265 is implanted such that one or morestimulation elements 260 are positioned proximate one or more peripheralnerves).

In some embodiments, one or more tines 266 are configured to bedeployed, such as via an operator-accessible control.

One or more stimulation elements 260 (singly or collectively stimulationelement 260) and/or functional element 299 (e.g. functional element 299a and/or 299 b) can comprise one or more sensors, transducers and/orother functional elements. In some embodiments, one or more stimulationelements 260 and/or functional elements 299 comprise at least one sensorand/or at least one transducer (e.g. a single stimulation element 260 ormultiple stimulation elements 260). In some embodiments, stimulationelement 260 and/or functional element 299 comprises a functional elementconfigured to provide a therapy, such as one or more stimulationelements 260 configured to deliver an agent to tissue (e.g. a needle orcatheter), to deliver energy to tissue and/or to otherwisetherapeutically affect tissue. In some embodiments, stimulation element260 and/or functional element 299 comprises one or more functionalelements configured to record patient information, such as whenstimulation element 260 and/or functional element 299 comprises one ormore sensors configured to measure a patient physiologic parameter, asdescribed herein. In some embodiments, stimulation element 260 and/orfunctional element 299 comprises one or more sensors configured torecord an implantable device 200 parameter, also as described herein.

One or more stimulation elements 260 can be positioned on lead 265 asshown in FIG. 1. Alternatively or additionally, one or more stimulationelements 260 can be positioned on housing 210. One or more functionalelements 299 can be positioned on lead 265 (e.g. functional element 299b shown) and/or positioned on and/or within housing 210 (e.g. functionalelement 299 a shown).

Stimulation element 260 can comprise one or more stimulation elementspositioned at one or more internal body locations. Stimulation element260 can comprise one or more stimulation elements positioned tointerface with (e.g. deliver energy to and/or record a physiologicparameter from) spinal cord tissue, spinal canal tissue, epidural spacetissue, spinal root tissue (dorsal or ventral), dorsal root ganglion,nerve tissue (e.g. peripheral nerve tissue, spinal nerve tissue orcranial nerve tissue), brain tissue, ganglia (e.g. sympathetic orparasympathetic) and/or a plexus. In some embodiments, stimulationelement 260 comprises one or more elements positioned proximate and/orwithin one or more tissue types and/or locations selected from the groupconsisting of: one or more nerves; one or more locations along, inand/or proximate to the spinal cord; peripheral nerves of the spinalcord including locations around the back; the knee; the tibial nerve(and/or sensory fibers that lead to the tibial nerve); the occipitalnerve; the sphenopalatine ganglion; the sacral and/or pudendal nerve;brain tissue, such as the thalamus; baroreceptors in a blood vesselwall, such as in the carotid artery; one or more muscles; the medialnerve; the hypoglossal nerve and/or one or more muscles of the tongue;cardiac tissue; the anal sphincter; the dorsal root ganglion; motornerves; muscle tissue; the spine; the vagus nerve; the renal nerve; anorgan; the heart; the liver; the kidney; an artery; a vein; bone; andcombinations of one or more of these, such as to stimulate and/or recorddata from the tissue and/or location in which the stimulation element260 is positioned proximate to and/or within. In some embodiments,apparatus 10, implantable device 200 and/or stimulation element 260 areconfigured to stimulate spinal nerves, peripheral nerves and/or othertissue as described in applicant's co-pending U.S. patent applicationSer. No. 15/916,023, titled “Apparatus for Peripheral or SpinalStimulation”, filed Mar. 8, 2018 [Docket nos. 47476-707.301;NAL-012-US].

In some embodiments, stimulation element 260 and/or functional element299 comprises one or more sensors configured to record data representinga physiologic parameter of the patient. Stimulation element 260 and/orfunctional element 299 can comprise one or more sensors selected fromthe group consisting of: electrode; sensor configured to recordelectrical activity of tissue; blood glucose sensor; gas sensor; bloodgas sensor; ion concentration sensor; oxygen sensor; pressure sensor;blood pressure sensor; heart rate sensor; cardiac output sensor;inflammation sensor; neural activity sensor; neural spike sensor;muscular activity sensor; EMG sensor, bladder volume sensor, bladderpressure sensor, gastric volume sensor; peristalsis rate sensor; pHsensor; strain gauge; accelerometer; gyroscope; GPS; respiration sensor;respiration rate sensor; flow sensor; viscosity sensor; temperaturesensor; magnetic sensor; optical sensor; MEMs sensor; chemical sensor;hormone sensor; impedance sensor; tissue impedance sensor;electrode-tissue interface impedance sensor; body position sensor; bodymotion sensor; organ motion sensor; physical activity level sensor;perspiration sensor; patient hydration sensor; breath monitoring sensor;sleep monitoring sensor; food intake monitoring sensor; digestionmonitoring sensor; urine movement sensor; bowel movement sensor; tremorsensor; pain level sensor; and combinations of one or more of these.

Apparatus 10 (e.g. via stimulation element 260, functional element 299,and/or functional element 599) can be configured to record a patientparameter (e.g. patient physiologic and/or patient environmentparameter) selected from the group consisting of: blood glucose; bloodpressure; EKG; heart rate; cardiac output; oxygen level; pH level; pH ofblood; pH of a bodily fluids; tissue temperature; inflammation level;bacteria level; type of bacteria present; gas level; blood gas level;neural activity; neural spikes; neural spike shape; action potential;local field potential (LFP); EEG; muscular activity (e.g. as measuredusing EMG); skeletal muscle activity; bladder volume; bladder pressure;gastric volume; peristalsis rate; impedance; tissue impedance;electrode-tissue interface impedance; physical activity level; painlevel; body position; body motion; organ motion; respiration rate;respiration level; perspiration rate; sleep level; sleep cycle;digestion state; digestion level; urine production; urine flow; bowelmovement; tremor; ion concentration; chemical concentration; hormonelevel; viscosity of a bodily fluid; patient hydration level; andcombinations of one or more of these.

In some embodiments, stimulation element 260 and/or functional element299 comprises one or more sensors configured to record data representinga parameter of implantable device 200. In these embodiments, stimulationelement 260 and/or functional element 299 can comprise one or moresensors selected from the group consisting of: an energy sensor; avoltage sensor; a current sensor; a temperature sensor (e.g. atemperature of one or more components of implantable device 200); acontamination detector (e.g. to detect undesired material that haspassed through housing 210); an antenna matching and/or mismatchingassessment sensor; power transfer sensor; link gain sensor; power usesensor; energy level sensor; energy charge rate sensor; energy dischargerate sensor; impedance sensor; load impedance sensor; instantaneouspower usage sensor; average power usage sensor; bit error rate sensor;signal integrity sensor; and combinations of one or more of these.Apparatus 10 can be configured to analyze (e.g. via implantablecontroller 250, programmer 600 and/or diagnostic assembly 62 describedherebelow) the data recorded by stimulation element 260 and/orfunctional element 299 to assess one or more of: power transfer; linkgain; power use; energy within energy storage assembly 270; performanceof energy storage assembly 270; expected life of energy storage assembly270; discharge rate of energy storage assembly 270; ripple or othervariations of energy storage assembly 270; matching of antenna 240 and540; communication error rate between implantable device 200 andexternal device 500; integrity of transmission between implantabledevice 200 and external device 500; and combinations of one or more ofthese. A stimulation element 260 can be configured to recordtemperature, such as when apparatus 10 is configured to deactivate orotherwise modify the performance of an implantable device 200 when therecorded temperature exceeds a threshold.

In some embodiments, one or more stimulation elements 260 comprise atransducer configured to deliver energy to tissue, such as to treat painand/or to otherwise stimulate or affect tissue. In some embodiments,stimulation element 260 comprises a stimulation element, such as one ormore transducers selected from the group consisting of: an electrode; anenergy delivery element such as an electrical energy delivery element, alight energy delivery element, a laser light energy delivery element, asound energy delivery element, a subsonic sound energy delivery elementand/or an ultrasonic sound delivery element; an electromagnetic fieldgenerating element; a magnetic field generating element; a mechanicaltransducer (e.g. delivering mechanical energy to tissue); a tissuemanipulating element; a heat generating element; a cooling (e.g.cryogenic or otherwise heat extracting energy) element; an agentdelivery element such as a pharmaceutical drug delivery element; andcombinations of one or more of these.

In some embodiments, one or more stimulation elements 260 comprises adrug or other agent delivery element, such as a needle, port,iontophoretic element, catheter, or other agent delivering element thatis connected to a reservoir of agent positioned within housing 210 (e.g.reservoir 225 described herebelow). In some embodiments, one or morestimulation elements 260 comprise a drug eluting element configured toimprove biocompatibility of implantable system 20.

In some embodiments, one or more stimulation elements 260 comprise oneor more electrodes configured to deliver energy to tissue and/or tosense a patient parameter (e.g. electrical activity of tissue or otherpatient physiologic parameter). In these embodiments, one or morestimulation elements 260 can comprise one or more electrodes selectedfrom the group consisting of: microelectrode; cuff electrode; array ofelectrodes; linear array of electrodes; circular array of electrodes;paddle-shaped array of electrodes; bifurcated electrodes; andcombinations of one or more of these.

In some embodiments, apparatus 10 (e.g. via stimulation element 260,functional element 299, and/or functional element 599) is configured toboth record one or more patient parameters, and also to perform amedical therapy (e.g. stimulation of tissue with energy and/or anagent). In these embodiments, the medical therapy can be performed in aclosed-loop fashion, such as when energy and/or agent delivery ismodified based on the measured one or more patient physiologicparameters.

In some embodiments, one or more stimulation elements 260 comprise anagent delivery element, such as a fluid delivery element (e.g. acatheter, a porous membrane, an iontophoretic element or a needle) influid communication with a reservoir of the agent positioned withinhousing 210, such as reservoir 225 described herebelow.

In some embodiments, apparatus 10 comprises one or more tools, tool 60shown. Tool 60 can comprise a data logging and/or analysis toolconfigured to receive data from external system 50 or implantable system20, such as data comprising: diagnostic information recorded by externalsystem 50 and/or implantable system 20; therapeutic information recordedby external system 50 and/or implantable system 20; patient information(e.g. patient physiologic information) recorded by implantable system20; patient environment information recorded by implantable system 20;and combinations of one or more of these. Tool 60 can be configured toreceive data from wired or wireless (e.g. Bluetooth) means. Tool 60 cancomprise a tool selected from the group consisting of: a data loggingand/or storage tool; a data analysis tool; a network such as a LAN orthe Internet; a cell phone; and combinations of one or more of these.

In some embodiments, tool 60 comprises a battery charging assembly, suchas an assembly configured to recharge one or more power supplies 570comprising a rechargeable battery or capacitor.

Apparatus 10 can include one or more placement tools, positioning tool67 shown, which can be configured to aid in the positioning and/ormaintenance of one or more external devices 500 on the patient's skin(e.g. at a location proximate an implanted implantable device 200).

Apparatus 10 can include one or more implantation tools, tool 65 shown.Implantation tool 65 can comprise an introducer, tunneller (e.g.tunneling tool 6504 described herein), and/or other implantation toolconstructed and arranged to aid in the implantation of housing 210,implantable antenna 240, lead 265 and/or one or more stimulationelements 260. In some embodiments, tool 65 comprises a componentconfigured to anchor implantable device 200 to tissue, such as a mesh orwrap that slides around at least a portion of implantable device 200 andis configured to engage tissue (e.g. via tissue ingrowth) or be engagedwith tissue (e.g. via suture or clips).

In some embodiments, one or more components (and/or portions ofcomponents) of tool 65 comprises a lubricious coating and/or a lubricousmaterial (“lubricious coating” herein), such as to reduce tissue traumaand/or reduce pain to the patient. For example, tool 65 can comprise anintroducer, tunneller, pocket formation tool, needle, and/or otherinsertion tool with at least a portion comprising a lubricious coatingconfigured to ease insertion of the tool. Typical coatings and materialsinclude but are not limited to: a polytetrafluoroethylene coating ormaterial; a hydrophilic coating or material; and combinations of these.

In some embodiments, one or more components (and/or portions ofcomponents) of tool 65 comprises one or more “visualizable portions”,such as a radiopaque portion that is visible in X-ray imaging (e.g.fluoroscopy) and/or ultrasonically visible portion that is visible inultrasound imaging. For example, tool 65 can comprise an introducerincluding an ultrasonically visible or otherwise visible portion that isused to position the introducer, such as during the implantation of lead265 or another portion of implantable device 200.

In some embodiments, lead 265 comprises a paddle lead or otherstimulating lead and tool 65 comprises an introducer (e.g. a needle oran extended-width introducer) configured to deliver at least a distalportion of lead 265 into an epidural space of a patient. Tool 65 cancomprise an introducer comprising a Tuohy needle, such as a Tuohy needleof 12 gauge or smaller. Tool 65 can comprise a handle for manipulatinglead 265. Tool 65 can be configured to place lead 265 at an entry pointabove the lumbar spinal column (e.g. between L1 and L2 vertebrae). Tool65 can include extension tubing used to insert lead 265. Tool 65 canfurther comprise a tool configured to anchor lead 265, such as when tool65 comprises sutures, clips, other anchoring elements and/or an anchorsecuring tool (e.g. a needle or a stapling device), such as to securelead 265 in subcutaneous tissue. Lead 265 and/or tool 65 can compriseextension tubing used to place lead 265, such as extension tubing thatremains in place after removal of an introducer of tool 65. Tool 65 canbe configured to place lead 265 against the dura of the spinal cord ofthe patient.

In some embodiments, tool 65 and/or lead 265 are constructed andarranged to implant lead 265 to stimulate one or more multifidus (MF)muscle fascicles, such as at least three sets of multifidus musclefascicles. Lead 265 can be secured to a vertebra (e.g. on the transverseprocess, lamina or vertebral body). Lead 265 can be placed via tool 65such that one or more stimulation elements 260 (e.g. electrodes) arepositioned within the multifidus muscle structures. One or morestimulation elements 260 can be positioned to deliver electrical energyand/or to otherwise stimulate tissue selected from the group consistingof: muscle motor point(s) or the deep fibers of lumbar multifidus;quadratus lumborum; the erector spinae; psoas major; transverseabdominis; connective tissue such as the annulus or facet capsule;ligaments coupling bony structures of the spine; and combinations of oneor more of these. Stimulation elements 260 can be positioned to:depolarize, hyperpolarize and/or block innervated sections of the musclethat will then propagate an activating and/or inhibiting stimulus alongthe nerve fibers recruiting muscle tissue remote from the site ofstimulation and/or modulate nerve activity (including inhibiting nerveconduction, improving nerve conduction and/or improving muscleactivity). In some embodiments, stimulation elements 260 are positionedto cause transvascular stimulation (e.g. transvascular stimulation fromarteries and/or veins in a leg or arm). In some embodiments, stimulationelements 260 are positioned to stimulate nerve tissue selected from thegroup consisting of: dorsal ramus nerve; medial branch of dorsal ramusnerve; nervous tissue associated with multifidus muscle; andcombinations of one or more of these. In some embodiments, stimulationelements 260 are configured to deliver stimulation energy to contractthe multifidus muscle. In some embodiments, stimulation elements 260 areconfigured to stimulate tissue by providing episodic electricalstimulation. In some embodiments, apparatus 10 comprises a tool 60configured to diagnose a defect in spinal muscle or the motor controlsystem. In some embodiments, apparatus 10 comprises a tool 60 configuredto test function of the multifidus muscle, such as when tool 60comprises an MRI; ultrasound imager; electromyogram; tissue biopsydevice; and/or a device configured to test displacement as a function ofload for a spine.

In some embodiments, two or more external system 50 components areconnected by a connecting filament, such as is described hereabove.Alternatively or additionally, two or more implantable system 20components are connected by a conduit, such as a connecting filament asdescribed herein. Alternatively or additionally, two more externalsystem 50 components and/or two or more implantable system 20 componentstransmit information and/or power via a wireless transmitter (e.g. an RFtransmitter), magnetic coupling, inductive coupling; capacitive couplingand/or other wireless transmission means.

Apparatus 10 can include one or more positioning devices, such aspatient attachment device 70 shown in FIG. 1, that is used to attach oneor more components of external system 50 to a location on or at leastproximate the patient. In some embodiments, patient attachment device 70is constructed and arranged as described in applicant's co-pending U.S.patent application Ser. No. 16/408,989, titled “Method and Apparatus forNeuromodulation Treatments of Pain and Other Conditions”, filed May 10,2019 [Docket nos. 47476.705.302; NAL-008-US-CON1].

Patient attachment device 70 can comprise one or more elementsconfigured to attach one or more external devices 500 and/or programmer600 at one or more locations on or proximate the patient's skin, thatare relatively close to one or more implantable devices 200 that havebeen implanted in the patient. Patient attachment device 70 can comprisea component selected from the group consisting of: belt; belt withpockets; belt with adhesive; adhesive; strap; strap with pockets; strapwith adhesive shoulder strap; shoulder band; shirt; shirt with pockets;clothing; clothing with pockets; epidural electronics packaging; clip(e.g. patient attachment device 70 a described herebelow in reference toFIG. 3A-D); bracelet; wrist band; wrist watch; anklet; ankle bracelet;knee strap; knee band; thigh strap; thigh band; necklace; hat; headband;collar; glasses; goggles; earpiece; behind-the-earpiece; andcombinations of one or more of these. In some embodiments, patientattachment device 70 comprises a belt configured to surround at leastone antenna 540 (e.g. at least one antenna 540 mounted to or otherwisepositioned on a printed circuit board such as a flexible printed circuitboard). Patient attachment device 70 can include one or more pockets,such as one or more pockets configured to collectively surround one ormore of: external device 500; one or more antennas 540; power supply570; programmer 600; and combinations of one or more of these. In someembodiments, patient attachment device 70 comprises multiple pockets,such as to allow repositioning of an external antenna 540, programmer600, external transmitter 530 and/or external power supply 570 tovarious different locations, such as to improve transmission of powerand/or data to one or more implantable devices 200 and/or improvepatient comfort. In some embodiments, one or more antennas 540, powersupplies 570, and/or transmitters 530 are connected through flexiblecables positioned in patient attachment device 70. In some embodiments,the flexible cables are small coax cables that accommodate the powerlevels and frequencies of the carried signals. In some embodiments, theone or more antennas 540 are connected to one or more additionalcomponents of external device 500 through a single cable with a localpower splitting component and/or active matching element that adjustssignal power to each of the one or more antennas 540.

In some embodiments, patient attachment device 70 and/or external device500 can be configured to prevent adversely affecting portions of theskin contacted by either device. Alternatively or additionally, patientattachment device 70 and/or external device 500 can be configured toclean and/or to promote healing of one or more skin-contacting portions.For example, patient attachment device 70 can include an agent (e.g. acoating or other included agent) selected from the group consisting of:a bactericidal agent; an anti-fungal agent; and combinations thereof.

In some embodiments, an anchoring-based tool, patient attachment device70, is used on a patient-by-patient basis, such as when used onoverweight patients and/or to otherwise avoid migration of implantabledevice 200 sideways and/or downward (e.g. into fat tissue).

Apparatus 10 can comprise a device configured to operate (e.g.temporarily operate) one or more implantable devices 200, such astrialing interface 80 shown in FIG. 1. Trialing interface 80 can beconfigured to wirelessly deliver power to an implantable device 200,wirelessly deliver data to an implantable device 200, and/or wirelesslyreceive data from an implantable device 200. Trialing interface 80 canbe configured to interface with one or more implantable devices 200during an implantation procedure in which one or more implantabledevices 200 are implanted in a patient (e.g. a sterile clinicalprocedure in which an implantable device 200 comprising a pre-attachedlead 265 is implanted in a patient). Trialing interface 80 can beconfigured to be sterilized one or more times. Trialing interface 80 cancomprise one or more antennas, such as an antenna similar to antenna 540of an external device 500. Trialing interface 80 can comprise atransmitter, such as a transmitter similar to transmitter 530 ofexternal device 500, and a power supply, such as a power supply similarto power supply 570 of external device 500. In some embodiments,trialing interface 80 is of similar construction and arrangement to thetrialing interface described in applicant's co-pending U.S. patentapplication Ser. No. 16/408,989, titled “Method and Apparatus forNeuromodulation Treatments of Pain and Other Conditions”, filed May 10,2019 [Docket nos. 47476.705.302; NAL-008-US-CON1]. In some embodiments,trialing interface 80 includes a housing to be positioned proximate atleast a portion of implantable device 200, such as a housing 210 thatsurrounds an antenna and a transmitter that is configured to operativelycouple to (e.g. transmit power and/or data to) one or more antennas 240of one or more implantable devices 200.

In some embodiments, trialing interface 80 is constructed and arrangedas described an applicant's co-pending U.S. patent application Ser. No.16/672,921, titled “Stimulation Apparatus”, filed Nov. 4, 2019 [Docketnos. 47476-714.301; NAL-020-US].

As described hereabove, trialing interface 80 can be used in clinicalprocedures in which an implantable device 200 including a pre-attachedlead 265 is implanted. In some embodiments, implantable device 200includes an attachable lead 265, and apparatus 10 includes trialinginterface 90. Trialing interface 90 can be configured to operably (e.g.electrically) attach to lead 265, such as to deliver stimulation energyvia a wired connection during a trialing procedure, as described herein.For example, trialing interface 90 can deliver stimulation energy to oneor more stimulation elements 260 of lead 265 during a trialing procedurein which proper position of stimulation element 260 is confirmed and/ormodified, and/or one or more stimulation waveforms are tested. Trialinginterface 90 can include an interface connector 95 configured tooperably attach (e.g. electrically attach) trialing interface 90 to lead265 (e.g. after lead 265 has been implanted in tissue of the patient).Connector 95 can be configured to be used in a single trialing procedure(e.g. on a single patient), while the remainder of trialing interface 90can be reused (e.g. in multiple trialing procedures for multiplepatients). Trialing interface 90 can comprise a device that issterilized, and it can be a device that can be re-sterilized (e.g. to beused in multiple sterile clinical procedures). In some embodiments,interface connector 95 and other portions of trialing interface 90 areconstructed and arranged as described herebelow in reference to FIGS.12A-B. In some embodiments, trialing interface 80 and trialing interface90 include similar components, (e.g. similar components used to createsimilar stimulation waveforms to be used in a trialing procedure).

In some embodiments, one or more implantable devices 200 of implantablesystem 20 comprises an implantable transmitter configured to transmitdata, such as to transmit data (e.g. stimulation information, patientphysiologic information, patient environment information, implantabledevice 200 performance and/or configuration information, and the like)to one or more external devices 500. In these embodiments, receiver 230can be configured as both a receiver and a transmitter. One or moreimplantable devices 200 can be configured to transmit data by sending asignal to (i.e. “driving”) one or more antennas 240 or another antennaof implantable device 200. An implantable device 200 can be configuredto transmit data using one or more of: load modulation; a signalcarrier; and/or body conduction. An implantable device 200 can beconfigured to adjust the transmission, such as to adjust a datatransmission parameter selected from the group consisting of: data rate;pulse width; duration of carrier signal; amplitude of carrier signal;frequency of carrier signal; configurable load; and combinations of oneor more of these.

In some embodiments, apparatus 10 comprises a diagnostic assembly,diagnostic assembly 62 shown in FIG. 1. In some embodiments, programmer600 and/or implantable controller 250 comprise all or a portion ofdiagnostic assembly 62. Diagnostic assembly 62 can be configured toassess, monitor, determine and/or otherwise analyze patient informationand/or implantable device 200 information, such as when one or morestimulation elements 260, functional elements 299, and/or functionalelements 599 are configured as a sensor configured to record patientinformation (e.g. patient physiologic information and/or patientenvironment information) and/or apparatus 10 information (e.g.implantable device 200 information) as described herein. Diagnosticassembly 62 can be configured to analyze communication and/or the powerlink between an implantable device 200 and an external device 500. Insome embodiments, such a communication link analysis can be performed bymeasuring bit error rate (BER) of a known data stream duringcommunication signal transmission (also referred to as “communicationlink”) measurement phase (e.g. such as during a calibration procedure).The BER can be tracked by the implant controller 250 or programmer 600,such as to monitor and keep track of any trends in the link. This trendcan be used to adjust the link and/or provide feedback to an operator ofapparatus 10 (e.g. the patient), in case the link cannot beautomatically adjusted to compensate for a negative trend (e.g. suchthat the operator can perform physical re-adjustment of the externalsystem 50). Alternatively or additionally, a power link analysis can beperformed by monitoring charge/discharge rate of the implanted energystorage assembly 270. Similar to the communication link, the power linkstatus and/or trending can be monitored and recorded for link adjustmentand/or feedback purposes. Diagnostic assembly 62 can be configured toanalyze a result of stimulation energy delivered by implantable device200, such as when a stimulation element 260 comprises an electrode torecord electrical activity of tissue (e.g. in addition to deliveringelectrical energy to stimulate tissue). A stimulation element 260, afunctional element 299, and/or a functional element 599 can comprise asensor configured to record neural activity and/or muscular activity,and the diagnostic assembly configured to analyze the recorded sensordata. In some embodiments, diagnostic assembly 62 is configured toanalyze impedance, such as when a stimulation element 260, a functionalelement 299, and/or functional element 599 comprises a sensor configuredto record data related to impedance, such as when implantable device 200performs a frequency sweep, performs an impulse response and/or comparesvoltage and current of a stimulation waveform. In some embodiments,diagnostic assembly 62 is configured to assess the impedance of one ormore implantable antennas 240 and/or one or more external antennas 540.In these embodiments, impedance can be assessed by performing a functionselected from the group consisting of: performing a frequency sweep;performing an impulse response; comparing voltage and current of awaveform; and combinations of one or more of these.

In some embodiments, diagnostic assembly 62 is configured to test orotherwise assess the link between one or more implantable antennas 240and one or more external antennas 540 (e.g. during a procedure in whichone or more implantable devices 200 are implanted in a patient). Inthese embodiments, diagnostic assembly 62 can be configured to perform atest prior to anchoring housing 210 to tissue (e.g. prior to initial orfinal suturing into tissue such as the fascia layer). For example, lead265 can be implanted at a location to stimulate target tissue (e.g. oneor more nerves identified to treat pain or another patient condition).Prior to suturing housing 210 in its implant location, diagnosticassembly 62 can be configured to confirm that one or more externalantenna 540 transmission links to one or more implantable antennas 240are above an efficiency threshold, for example such that sufficientpower will be received by the one or more implantable devices 200.Additionally, the procedure can be performed to optimize or otherwiseimprove the position of the one or more implantable devices 200 to beimplanted and subsequently secured to tissue.

In these link testing embodiments, diagnostic assembly 62 can comprise ahandheld assembly (e.g. a sterile assembly comprising a wand or otherhandheld housing). Diagnostic assembly 62 can be configured to send asimple signal to one or more implantable devices 200 (e.g. a diagnosticassembly 62 with similar power and/or data transmission capabilities asan external device 500). Each implantable device 200 can respond (e.g.via data sent via an implantable antenna 240 or other transmitter) withinformation related to the quality of the transmission link (e.g.information about the power received by the one or more implantabledevices 200). Diagnostic assembly 62 could provide a user interface(e.g. a speaker, a text screen and/or a video display) that providesquality or other information (go/no go information, digital or otherdiscrete level information, and/or analog information). Diagnosticassembly 62 could be further configured to provide informationconfirming detection of one or more implantable devices 200, status ofone or more implantable devices 200 (e.g. parameter level and/or faultdetection status), and/or self-diagnostic status (i.e. diagnosticassembly 62 status).

Each implantable device 200 can be configured to specifically identifyand/or specifically reply to diagnostic assembly 62 (e.g. in a differentform than communications with an external device 500). Each implantabledevice 200 can be configured to provide information related to one ormore of: the charge and/or discharge rate of energy storage assembly 270(e.g. the charge and/or discharge rate of a capacitor or battery ofenergy storage assembly 270); or the frequency of a voltage-controlledoscillator that is driven by an unregulated voltage of power converter233. Diagnostic assembly 62 can be configured to perform numerousperformance tests (e.g. of one or more implantable devices 200 orimplantation locations for one or more implantable devices 200), priorto completion of the implantation procedure (e.g. prior to closing oneor more incisions).

In some embodiments, apparatus 10 is configured to provide a therapy bydelivering stimulation energy to tissue, such as electrical energydelivered to tissue by one or more stimulation elements 260 comprisingone or more electrodes. Alternatively or additionally, apparatus 10 canbe configured as an agent-delivery apparatus (e.g. a pharmaceutical orother agent delivery apparatus). In some embodiments, apparatus 10comprises one or more reservoirs for storing the agent, such asreservoir 525 of external device 500 and/or reservoir 225 of implantabledevice 200, each shown in FIG. 1. Reservoirs 525 and/or 225 can befluidly connected to one or more functional elements 599 and/orfunctional elements 299, respectively (e.g. via one or more tubes).Reservoirs 525 and/or 225 can comprise one or more chambers (e.g.independent chambers configured to separately contain incompatible drugsor otherwise prevent undesired multiple drug interactions). Reservoirs525 and/or 225 can comprise a volume (e.g. a volume to store one or moreagents) between 0.1 ml and 50 ml, such as between 0.1 ml and 3.0 ml, orbetween 0.1 ml and 1.0 ml. Reservoirs 525 and/or 225 can comprisepressurized reservoirs or otherwise comprise a fluid pumping mechanism(e.g. a peristaltic mechanism, syringe pump or other fluid pump).Reservoirs 525 and/or 225 and can comprise refillable reservoirs (e.g.when reservoir 225 of an implantable device 200 comprises a valvedopening such as a silicone septum or a mechanical valve, eitheraccessible via a needle for refilling). The fluidly attached functionalelements 599 and/or functional elements 299 can comprise a fluiddelivery element selected from the group consisting of: a catheter; aporous membrane; an iontophoretic element; a needle; or combinations ofone or more of these. Delivered and/or stored (e.g. in a reservoir)agents can comprise an agent selected from the group consisting of: ananalgesic agent such as morphine, fentanyl, lidocaine or other agentdelivered to treat pain; a chemotherapeutic agent such as achemotherapeutic agent delivered systemically (e.g. throughout the bloodsystem of the patient) and/or to a location in or proximate an organsuch as the liver or brain to treat cancer; an antibiotic configured totreat or prevent an infection; a hormone such as a hormone deliveredintravenously in hormonal therapy; heart medications such asnitroglycerin, a beta blocker or a blood pressure lowering medication; acarbohydrate such as glucose or dextrose delivered to treat a low bloodsugar condition; insulin such as to treat a high blood sugar condition;a diabetic medication; a neurological medication; an epilepsymedication; and combinations of one or more of these. In someembodiments, apparatus 10 comprises the one or more agents stored inreservoir 225 and/or 525. In some embodiments, apparatus 10 isconstructed and arranged to deliver the agent (e.g. via a catheter-basedfunctional element 599, functional element 299, and/or stimulationelement 260) to a patient location selected from the group consistingof: a vessel; a blood vessel; a vein; an artery; heart; brain; liver;spine; epidural space; intrathecal space; subcutaneous tissue; bone;intraperitoneal space, intraventricular space, and combinations of oneor more of these.

In some embodiments, an external device 500 is attached to the patientvia a patient attachment device 70 comprising a wrist band, wrist watch,leg band, ankle band or other band configured to position an externaldevice 500 about a limb of the patient (i.e. arm or leg of the patient).In these embodiments, one or more implantable devices 200 are implantedunder the skin proximate the intended (limb) location of external device500 and patient attachment device 70. Apparatus 10 can be configuredsuch that external device 500 comprises one or more antennas 540; one ormore implantable devices 200 each comprise one or more antennas 240; andeach implantable device 200 one or more antennas 240 receive powerand/or data from the one or more antennas 540 of the limb-attachedexternal device 500. The limb-attached external device 500 can compriseone or more reservoirs 525 described hereabove and/or one or morefunctional elements 599 configured as agent delivery elements and/orsensors. The one or more implantable devices 200 can comprise one ormore reservoirs 225 described hereabove and/or one or more stimulationelements 260 configured as agent delivery elements and/or sensors.

In some embodiments, apparatus 10 comprises an agent delivery apparatusand agent is delivered into the patient (e.g. into a blood vessel,muscle or subcutaneous tissue) by an external device 500 functionalelement 599 (e.g. a needle) based on signals recorded by an implantabledevice 200 functional element 299 and/or stimulation element 260 (e.g. asensor). Alternatively or additionally, agent can be delivered into thepatient (e.g. into a blood vessel, muscle or subcutaneous tissue) by animplantable device 200 stimulation element 260 (e.g. a needle, catheter,porous membrane or iontophoretic delivery element). The amount of agentdelivered by stimulation element 260 can be based on signals recorded byan implantable device 200 stimulation element 260 (e.g. a sensor) and/oran external device 500 functional element 599 a (e.g. a sensor).External device 500 can provide power to one or more implantable devices200 and/or it can send data (e.g. sensor data from a functional element599) to implantable device 200, such as to control agent delivery byimplantable device 200.

Apparatus 10 can be configured to prevent an electromagnetic field (e.g.an electromagnetic field produced by one or more devices not included inapparatus 10 and/or other present in the patient environment) fromadversely affecting and/or otherwise affecting the patient treatmentand/or patient information recording (e.g. patient tissue stimulationand/or patient physiologic information gathering) performed by apparatus10. Electromagnetic fields from one or more apparatus 10 devices and/orotherwise present in the patient environment can potentially interferewith apparatus 10. The architecture of the wireless signal transmissionsof apparatus 10 can be configured to include certain unique and/oridentifiable patterns in the signals transmitted by apparatus 10 toconfirm (upon receipt) that the signal originated from a component ofapparatus 10. Alternatively or additionally, the stimulation signalproduced by an implantable device 200 can be created independent from apower signal received from an external device 500, so that anyelectromagnetic interference in the wireless link does not affectgeneration and delivery of the stimulation signal. In some embodiments,each implantable device 200 and/or external device 500 includes uniqueidentification codes that are required to be transmitted prior to anychanges in stimulation or other implantable device 200 configuration,ensuring correct operation in the presence of interference.Alternatively or additionally, the communication link can incorporatehandshaking protocols, confirmation protocols, data encryption and/orscrambling, coding and other security measures to ensure thatinterfering signals do not adversely affect the implantable system 20performance (e.g. stimulation). In some embodiments, external system 50and/or implantable system 20 incorporate electromagnetic absorptiveand/or reflective materials to minimize external interference from othersources and/or minimize the probability of apparatus 10 interfering withother systems. Alternatively or additionally, apparatus 10 canincorporate error detection and protocols for entering an alarm state(e.g. and shutting down normal operation) and/or otherwise ensuring safeoperation.

In some embodiments, implantable system 20 of apparatus 10 is configuredto perform magnetic field modulation, such as targeted magnetic fieldneuromodulation (TMFN), electro-magnetic field neuromodulation, such astargeted electro-magnetic field neuromodulation (TEMFN), transcutaneousmagnetic field stimulation (TMS), or any combination of these. Eachimplantable device 200, via one or more of its stimulation elements 260(e.g. electrodes) can be configured to provide localized (e.g. targeted)magnetic and/or electrical stimulation. Combined electrical fieldstimulation and magnetic field stimulation can be applied by usingsuperposition, and this combination can reduce the overall energyrequirement. In some embodiments, implantable apparatus 10 comprises oneor more stimulation elements 260 comprising a magnetic field generatingtransducer (e.g. microcoils or cuff electrodes positioned to partiallysurround or otherwise be proximate to one or more target nerves).Stimulation elements 260 comprising microcoils can be aligned withnerves to minimize affecting non-targeted tissue (e.g. to avoid one ormore undesired effects to non-target tissue surrounding or otherwiseproximate the target tissue). In some embodiments, the target tissuecomprises dorsal root ganglia (DRG) tissue, and the non-target tissuecomprises ventral root tissue (e.g. when the stimulation energy is belowa threshold that would result in ventral root tissue stimulation).

In some embodiments, external system 50 of apparatus 10 is configured toprovide mechanically adjustable alignment of one or more externalantennas 540 alignment. Link gain between one or more external antennas540 and one or more implantable antennas 240 can degrade over time dueto physical misalignment of the antennas, relative orientation changesbetween antennas and/or relative angular misalignment between antennas.In order to compensate for misaligned antennas, electrical beam steeringcan be included in apparatus 10. Antennas comprising a multi-feedantenna structure and/or those comprising an array of antennas can beincorporated (e.g. into external antenna 540, implantable antenna 240 orboth) for electrical beam steering. Alternatively or additionally,mechanical antenna steering can be implemented to physically realign oneor more external antennas 540 with one or more implanted antennas 240(or vice versa). A substrate of an implantable antenna 240 and/or anexternal antenna 540 can be flexible and/or rigid (e.g. a substratecomprising polyamide, polyimide, liquid crystal polymer (LCP), Rogers,FR4, or a similar material). One or more antennas 540 can be connectedto electronics (e.g. a transmitter, receiver or transceiver) using aflexible waveguide or cable (e.g. 50 ohm 0.047″ coaxial cable designedto provide patient comfort) and/or a flexible PCB substrate transmissionline. Mechanical or physical realignment of antennas 240 and/or 540 canbe accomplished using one or more of: use of motorized positioners, suchas a mechanism including one or more small pulleys and/or tensionersused to translate one or more antennas 240 and/or 540 about one or moreaxes; an actuator (e.g. a piezoelectric actuator) with directional gearsconfigured to translate one or more antennas 240 and/or 540 about one ormore axes; a micro-pump with fluid reservoir (e.g. liquid or gasreservoir) configured to hydraulically and/or pneumatically translateone or more antennas 240 and/or 540 about one or more axes, such as bycreating a local pressure difference. In some embodiments, a micro-pumpwith fluid reservoir is used to move one or more antennas 240 and/or540, such as to move an external antenna 540 away from tissue to reducespecific absorption rate (SAR). In these embodiments, external antenna540 can be positioned in mechanical contact with an expandable reservoir(e.g. a balloon) positioned between external antenna 540 and tissue. Thereservoir can be inflated or deflated to control separation distance ofthe external antenna 540 from the patient's skin surface. In someembodiments, apparatus 10 comprises one or more algorithm positioningalgorithms, algorithm 15, beam steering functionality and/or mechanicalantenna steering as described in applicant's co-pending U.S. patentapplication Ser. No. 14/975,358, titled “Method and Apparatus forMinimally Invasive Implantable Modulators”, filed Dec. 18, 2015 [Docketnos. 47476.703.301; NAL-005-US], and U.S. patent application Ser. No.15/664,231, titled “Medical Apparatus Including an Implantable Systemand an External System”, filed Jul. 31, 2017 [Docket nos. 47476-706.301;NAL-011-US], the content of each of which is incorporated herein in itsentirety for all purposes.

In some embodiments, implantable system 20 of apparatus 10 is configuredto provide paresthesia-reduced (e.g. paresthesia-free) high frequencypain management and rehabilitation therapy (e.g. via delivery of astimulation signal above 600 Hz or 1 kHz, or other stimulation signalresulting in minimal paresthesia). Apparatus 10 can be configured toprovide both low frequency (e.g. <1 kHz) stimulation and high frequencystimulation, such as when providing low frequency stimulation to elicitfeedback from a patient during intraoperative or other (e.g.post-implantation) stimulation configuration. For example, trialinginterface 80 and/or 90 can be used during an intra-operative titrationof stimulation configuration using low frequency stimulation (e.g. toposition and/or confirm position of one or more stimulation elements260, such as to confirm sufficient proximity to target tissue to bestimulated and/or sufficient distance from non-target tissue not to bestimulated). In some embodiments, high frequency stimulation isdelivered to reduce pain over extended periods of time, and lowfrequency stimulation is used in these intraoperative and/orpost-implantation titration or other stimulation configurationprocedures. Intentional elicitation of paresthesia (e.g. via lowfrequency stimulation and/or high frequency stimulation) is beneficialduring stimulation element 260 (e.g. electrode) implantation because apatient can provide feedback to the implanting clinician to ensure thatthe stimulation elements 260 are positioned close to the targetneuromodulation or energy delivery site. This implantationposition-optimizing procedure can advantageously reduce the requiredstimulation energy due to stimulation elements 260 being closer totarget tissue, since a minimum threshold for efficacious stimulationamplitude is proportional to the proximity of stimulation elements 260to target tissue (e.g. target nerves). The patient can inform theclinician of the sensation of paresthesia coverage, and the cliniciancan adjust stimulation element 260 position to optimize stimulationelement 260 location for efficacious treatment while minimizingunintentional stimulation of non-target tissue (e.g. motor nerves orother nerves which are not causing the patient's pain). Theseparesthesia-inducing techniques (e.g. using low frequency stimulationand/or high frequency stimulation) can be used during or afterimplantation of one or more implantable devices 200.

In some embodiments, apparatus 10 is configured to deliver low frequencystimulation energy (e.g. electrical energy comprising a low frequencysignal) to stimulate motor nerves, such as to improve tone andstructural support (e.g. physical therapy). In these embodiments,apparatus 10 can be further configured to provide high frequencystimulation, such as to treat pain (e.g. suppress and/or control pain).The combined effect can be used not only for pain management but alsomuscle strengthening and gradual healing of supportive structures.Alternatively or additionally, as described herein, apparatus 10 can beconfigured to deliver low frequency stimulation energy (e.g. electricalenergy) to induce paresthesia, which can also be accompanied by thedelivery of high frequency stimulation (e.g. to suppress and/or controlpain). In some embodiments, apparatus 10 is configured to deliver lowfrequency stimulation (e.g. electrical energy comprising a low frequencysignal) and burst stimulation, delivered simultaneously or sequentially.The low frequency stimulation and the burst stimulation can be deliveredon similar and/or dissimilar stimulation elements 260 (e.g. similar ordissimilar electrode-based stimulation elements 260).

As described herein, apparatus 10 can be configured for treatingnumerous disease and disorders, such as when apparatus 10 is configuredto deliver electrical or other stimulation energy to treat pain (e.g. bydelivering electrical or other energy to the spine or other neurallocation). Apparatus 10 can be configured to stimulate tissue withvarious stimulation waveforms, such as those described in applicant'sco-pending U.S. patent application Ser. No. 16/104,829, titled“Apparatus with Enhanced Stimulation Waveforms”, filed Aug. 17, 2018[Docket nos. 47476-708.301; NAL-014-US].

Apparatus 10 can be configured to treat neuropathy, neuralgia and/orother nerve pain that is related to: surgery; trauma; infection (e.g. aherpetic infection); and/or diabetes (e.g. diabetic neuropathy). One ormore stimulation elements 260 can be configured to deliver stimulationenergy (e.g. electrical energy, magnetic energy, light energy, thermalenergy, sound energy, and/or chemical energy (e.g. energy from a drug orreagent) to nerve tissue such as tissue of the central nervous systemand/or peripheral nervous system. One or more leads 265 (each comprisingone or more stimulation elements 260) can be implanted in and/orproximate the spinal cord, the groin and/or a joint such as the hip. Forexample, apparatus 10 can be configured to treat one or more of:post-surgical neuralgia (e.g. following hernia repair such as a herniarepair including an implanted mesh); headache (e.g. due to occipitalneuralgia); post-herpetic neuralgia; chronic pelvic and/or hip pain;knee pain; and combinations of one or more of these.

To treat pain related to hernia or hernia repair, one or morestimulation elements 260 (e.g. on a lead 265 and/or on a housing 210)can be positioned to stimulate tissue of the peripheral nervous systemand/or the central nervous system. In some embodiments, one or morestimulation elements 260 are positioned to stimulate the cutaneousbranch of the ilioinguinal, inguinal and/or genital branch of thegenitofemoral nerves. In some embodiments, one or more stimulationelements 260 are positioned to stimulate corresponding branches ofspinal nerves correlating to one or more dermatomes related to painassociated with at least one of hernia or hernia repair.

Hernia or hernia repair can lead to: inguinal pain; ilioinguinalneuralgia; post-traumatic neuropathic pain; ilioinguinal nerveentrapment; neuropathic pain of ilioinguinal origin; post-surgicalinguinal pain; genitofemoral pain; genitofemoral neuralgia;genitofemoral nerve entrapment; neuropathic pain of genitofemoralorigin; post-surgical genitofemoral pain; iliohypogastric pain;iliohypogastric neuralgia; iliohypogastric nerve entrapment; neuropathicpain of iliohypogastric origin; post-surgical iliohypogastric pain;testicular pain; scrotal pain; penis pain; groin pain; thigh pain; analpain; rectal pain; perineal pain; abdominal adhesions; pelvic adhesions;scar pain; diffuse polyneuropathy; and combinations of one or more ofthese. In some embodiments, apparatus 10 is configured to treat herniapain by delivering a low frequency stimulation signal (e.g. anelectrical signal less than or equal to 1 kHz delivered by one or moreelectrode-based stimulation elements 260). Alternatively oradditionally, apparatus 10 can treat hernia pain with a high frequencystimulation signal, such as a signal comprising a frequency greater than1 kHz. Stimulation can be accomplished either via subcutaneous fieldstimulation and/or by stimulation elements 260 positioned adjacent or atleast near the nerves and/or their branches. In some embodiments,stimulation is accomplished transvascularly (e.g. stimulation includinglow and/or high frequencies).

The apparatus of the present inventive concepts can be configured tostimulate the ilioinguinal nerve, genitofemoral nerve and/oriliohypogastric nerves, such as to ameliorate pain following herniarepair. One or more leads 265 (e.g. one or more leads 265 comprising oneor more electrode-based or otherwise stimulation-based stimulationelements 260) can be inserted over the inguinal region (which mayinclude the inguinal ring) to stimulate any or all three of these nerves(e.g. in a unilateral or bilateral fashion). Both the ilioinguinal andgenital branch of the genitofemoral nerves pass through the inguinalring. The anterior cutaneous iliohypogastric and femoral branch of thegenitofemoral nerve can be stimulated at one or more locations proximatebut rostral (iliohypogastric) or lateral (genitofemoral) to the inguinalring. Leads 265 can comprise one or more stimulation elements 260comprising cylindrical, paddle, cuff and/or hemi-cuff electrodes(electrodes placed surgically near and/or around these nerves). Thenerves can be localized via ultrasound or other imaging modalities.Contrast can be used to image the vessels nearby (e.g. the testicularand/or ovarian vein and/or artery). The genital branch of thegenitofemoral nerve can be stimulated in a transvascular manner throughthe testicular vein and/or artery. The genitofemoral and/or theilioinguinal nerves can also be stimulated (e.g. transvascularlystimulated) through the femoral vein and/or artery, or via thesuperficial or deep external pudendal vein and/or artery, and/or via thesuperficial epigastric vein and/or artery.

The painful areas innervated by the ilioinguinal nerve, genitofemoralnerve and/or iliohypogastric nerves, can also be treated via spinal cordstimulation provided by apparatus 10 in the L1-L5 region of the spinalcord. In some embodiments, direct stimulation of the L1-L2 dorsal rootganglia is provided in a similar treatment. Leads 265 (e.g. percutaneousor paddle) including stimulation-based stimulation elements 260 can beplaced over the dorsal columns, over the dorsal roots and/or in thedorsal root entry zone, in a unilateral, bilateral and/or midlinefashion.

To treat occipital neuralgia, also known as C2 neuralgia, one or morestimulation elements 260 can be positioned to stimulate peripheral nervetissue to reduce pain. Occipital neuralgia is a medical conditioncharacterized by chronic pain in the upper neck, back of the head and/orbehind the eyes (areas corresponding to the locations of the lesser andgreater occipital nerves). In some embodiments, one or more leads 265,each comprising one or more stimulation elements 260, are implantedtransversely, either unilaterally or bilaterally, at the level of theappropriate target cervical nerve (C1, C2, etc.). The C1, 2, 3 cervicalroots include the greater occipital nerve which originates primarilyfrom C2, and the lesser occipital nerves. Relevant trigeminal branchesinclude both the supraorbital and supratrochlear nerves from V1, theinfraorbital branches from V2, and the superficial temporal nerves fromV3. A partial convergence of these two systems occurs at theTrigemino-Cervical Complex (TCC). In some embodiments, one or morestimulation elements 260 are positioned to stimulate the trigeminaland/or occipital nerves. One or more leads 265 can be anchored to thefascia proximate the tissue to be stimulated.

To treat post-herpetic neuralgia (e.g. neuralgia associated withshingles), one or more stimulation elements 260 can be positioned tostimulate corresponding branches of the spinal nerves and/or peripheralnerves correlating to one or more dermatomes related to the patient'sshingles.

In some embodiments, apparatus 10 is configured to treat pelvic, bladderand/or bowel disorders, such as by stimulating sacral, pudendal and/ortibial nerves. In some embodiments, apparatus 10 is configured to treatpelvic pain by stimulating the tibial nerve.

Apparatus 10 can be configured to treat a bladder, bowel or otherdysfunction selected from the group consisting of: overactive bladder;urinary urgency; urinary frequency; urinary urgency frequency; urinaryurge incontinence; urinary stress incontinence; urge incontinence;stress incontinence; non-obstructive urinary retention; female sexualdysfunction; fecal incontinence; accidental bowel leakage; constipation;diarrhea; irritable bowel syndrome; colitis; detrusor instability;detrusor dysfunction; spastic bladder; neurogenic bladder; detrusorsphincter dyssynergia; detrusor hyperreflexia; detrusor areflexia; andcombinations of one or more of these.

Apparatus 10 can be configured to treat a pelvic disorder selected fromthe group consisting of: pelvic pain; painful bladder syndrome; Hunner'sulcers or lesions; interstitial cystitis; pelvic floor dysfunction;endometriosis; vulvodynia; dyspareunia; pelvic adhesions; abdominaladhesions; irritable bowel syndrome; pelvic girdle pain; pudendal nerveentrapment; pudendal neuralgia; dysmenorrhea; Müllerian abnormalities;pelvic inflammatory disease; ovarian cysts; ovarian torsion; Loin painhematuria syndrome; proctitis; prostatitis; prostadynia; post-abdominalsurgical pain; post-pelvic surgical pain; hernia pain; post-herniasurgical pain; anal pain; rectal pain; perineal pain; groin pain; vulvarpain; vaginal pain; clitoral pain; colitis; and combinations of one ormore of these.

Apparatus 10 can be configured to treat one or more of the pelvicdisorders, bladder dysfunctions and/or and bowel dysfunctions listedabove, by stimulating (e.g. using bilateral and/or unilateralstimulation) one or more of the targets listed below.

In some embodiments, the stimulated targets include the sacral nerves(roots) S2, S3 and/or S4. One or more leads 265 (e.g. each including oneor more stimulation-delivering stimulation elements 260) can bepositioned to stimulate any or all of the three roots, on a single sideor both sides, in any bilateral or unilateral combination. The roots canbe accessed, with the patient lying in the prone position, bypositioning one or more leads 265 (e.g. percutaneously), with or withoutthe use of fluoroscopy, ultrasound or any other imaging modality, intoone/any of the sacral foramen(a) from the posterior aspect of thesacrum. One or more leads 265 can be passed through the foramen to theanterior side of the sacrum, and/or one or more leads 265 can remaininside the foramen(a).

In some embodiments, the sacral roots are approached rostrally, via thesacral canal in a retrograde manner. In these embodiments, one or moreleads 265 can be passed through the ligamentum flavum, just caudal to L5or via any of the intervertebral spaces from L5 to T12, into the spinalcanal. One or more leads 265 are then threaded, with or without the aidof visualization (fluoroscopy, ultrasound or other imaging modality), ina caudal (retrograde) manner to enter the sacral canal. One or moreleads 265 can be placed along the sacral canal, and each root can bestimulated individually and/or each root can be stimulated in concert,via one or more leads 265 positioned along the internal surface of thesacral canal, and spanning one or more foramina.

In some embodiments, one or more leads 265 are threaded from the spinalcanal into each and/or all sacral foramen(a), in an anterior direction.The sacral canal can also be accessed caudally by one or more leads 265,via the sacral hiatus in an anterograde manner.

In some embodiments, the sacral roots (S2, S3 and/or S4) are accessed asthey enter the spinal cord at the cauda equina. This access can beachieved by inserting the one or more leads 265 through the ligamentumflavum, at a location just caudal to L5, or via any of theintervertebral spaces from L5 to T12, into the spinal canal. The one ormore leads 265 can then be threaded, with or without the aid ofvisualization (fluoroscopy, ultrasound or other imaging modality), up tothe cauda equina, where the S2, S3 and/or S4 roots can be stimulatedwhere they enter the spinal cord, and/or the conus medullaris can bestimulated directly (e.g. in the same location).

In some embodiments, the pudendal nerve is stimulated through one ormore different approaches. The pudendal nerve contains both afferent andefferent fibers carried by S2, S3 and S4 roots. The pudendal fibers exitAlcock's canal near the ischial spine, where they spread out toinnervate to the bladder wall, perineum, anus, genitals and urethra.Pelvic and voiding disorders can be treated by stimulating pudendalnerve fibers. The fibers can be accessed at the Alcock's canal viavarious approaches. In one embodiment, a transperineal approach isachieved by positioning the patient in the lithotomy position andinserting the lead 265 midpoint between the ischial tuberosity and theanus. A lead 265 is inserted toward the ischial spine, which can bepalpated transvaginally or transrectally. The ischial spine can also bevisualized through a number of imaging modalities (e.g. fluoroscopy,x-ray, ultrasound, and the like). In another embodiment, a transvaginalapproach is achieved by positioning the patient in the lithotomyposition and inserting a lead 265 through the vaginal wall, adjacent tothe ischial spine (e.g. through the vaginal wall toward the ischialspine). In another embodiment, a posterior approach is achieved bylaying the patient in the prone position and inserting a lead 265 justmedial to the ischial tuberosity toward the ischial spine. Thisinsertion can be facilitated by rectal palpation of the ischial spineand through visualization via a number of imaging modalities (e.g.fluoroscopy, x-ray, ultrasound, and the like).

In some embodiments, apparatus 10 is configured to stimulate pudendalafferents, such as by stimulating the dorsal genital nerve. These fibersare located just below the skin on the dorsum of the penis or justrostral to the clitoris. In some embodiments, pudendal afferents arestimulated periurethrally. One or more leads 265 can be insertedalongside the urethra to stimulate the pudendal fibers.

In some embodiments, apparatus 10 is configured to stimulate tibialnerve fibers, such as to treat one or more pelvic disorders (e.g.voiding dysfunction). In order to provide stimulation of the tibialnerve, lead 265 can be inserted at a location close to the knee and/orat a location near the ankle. For example, the tibial nerve can beaccessed a few mm below the skin surface in the ankle immediatelyposterior to the medial malleolus. Lead 265 can comprise a cylindricalSCS-type lead, which can be inserted percutaneously in this location.Alternatively or additionally, a direct (surgical) cut-down procedurecan be used to insert a cylindrical lead or to apply a cuff electrodedirectly to the nerve. The tibial nerve can also be accessedapproximately half way up the lower leg adjacent to the tibia. One ormore leads 265 can be inserted percutaneously in this location.Alternatively or additionally, a direct cut-down can be used to insertlead 265 (e.g. a cylindrical lead or a cuff electrode and/or hemi-cuffelectrode applied directly to the nerve in the mid-shin location).Tibial nerve fibers can be accessed in the popliteal fossa behind theknee, for example percutaneously with a lead 265 comprising acylindrical lead, and/or via a direct cut-down, for example with a lead265 comprising either a cylindrical or cuff electrode.

In some embodiments, apparatus 10 and one or more leads 265 areconstructed and arranged to stimulate the tibial and/or pudendal nervesvia a transvascular approach (i.e. stimulation energy delivered frominside a blood vessel to nerve tissue proximate the blood vessel), suchas via the femoral vein and/or artery, each of which provideintraluminal access to many other blood vessels (e.g. using standardinterventional techniques). The tibial nerve can be transvascularlystimulated by the popliteal vein and/or artery (e.g. by placing one ormore stimulation elements 260 in the popliteal vein and/or artery), at alocation behind the knee. The popliteal vein and/or artery can beintraluminally accessed from the femoral artery and vein. The tibialnerve also passes near the small saphenous vein, where it branches offof the popliteal vein. The posterior tibial vein and/or artery arepositioned adjacent to the tibial nerve, from the knee to the foot. Oneor more leads 265 can utilize one or more of these above locations tostimulate the tibial nerve.

In some embodiments, apparatus 10 and one or more leads 265 areconstructed and arranged to stimulate the pudendal nerve and/or sacralroots, such as using a lead 265 placed via the femoral vein and/orartery, which in turn provides intraluminal access to many vessels. Oneor more leads 265 can be configured to utilize any of the followingarteries and veins to stimulate the pudendal nerve and/or the sacralroots. One or more leads 265 can be constructed and arranged tostimulate a target site via a blood vessel selected from the groupconsisting of: the internal pudendal artery or vein (which branch off ofcommon iliac artery or vein, respectively); the inferior and superiorgluteal vein and/or artery; middle rectal, pudendal plexus and internaliliac vein and/or artery; medial and lateral sacral vein and/or artery;uterine and obturator vein and/or artery; and combinations of one ormore of these.

In some embodiments, apparatus 10 is configured to treat pelvicdysfunction, overactive bladder, and/or urinary incontinence (singly orcollectively “overactive bladder” herein). In some embodiments,apparatus 10 is configured to treat overactive bladder such as to reducethe effects of overactive bladder and/or to decrease use of one or moremedications taken by the patient to treat overactive bladder. In someembodiments, one or more stimulation elements 260 are positioned tostimulate tissue of the central nervous system or tissue and/or tissueof the peripheral nervous system to treat overactive bladder, such as tostimulate one or more nerves that control and/or are otherwise relatedto bladder function (e.g. to increase bladder capacity, improve bladderemptying, reduce urge incontinence and/or reduce stress incontinence).For example, one or more stimulation elements 260 are be positioned tostimulate tibial nerve tissue and/or sacral nerve tissue (e.g. at leastthe S3 nerve root) to treat overactive bladder. In some embodiments, oneor more stimulation elements 260 can be positioned to stimulate sacralnerve tissue to treat urinary urgency, urinary frequency (e.g. urinaryurgency frequency), and/or painful bladder syndrome. In someembodiments, lead 265 is constructed and arranged to be positioned alongone or more locations of the tibial nerve, such as a positioningperformed using percutaneous technique (e.g. when lead 265 comprises acylindrical SCS-type lead) and/or surgical (cut-down) techniques (e.g.when lead 265 comprise a cuff electrode and/or hemi-cuff electrodeapplied directly to the nerve). The tibial nerve branches off of thesciatic nerve just above the knee, and runs along the length of thetibia, medial and lateral to the tibia. The tibial nerve then passesposterior to the medial malleolus prior to innervating the plantarsurface of the foot. Lead 265 can be constructed and arranged to accesssites proximate the tibial nerve percutaneously and/or through anincision at the back of the knee in the popliteal fossa, along the tibiaor behind the medial malleolus. The housing 210 can be placed anywherein the leg when stimulating the tibial nerve. Lead 265 can beconstructed and arranged to stimulate the tibial nerve through atransvascular approach, via the femoral vein and/or artery, each ofwhich provide intraluminal access to many vessels. The tibial nerve canbe accessed by the popliteal artery and vein behind the knee, which areintraluminally accessible from the femoral artery and vein,respectively. The tibial nerve also passes near the small saphenousvein, where it branches off of the popliteal vein. The posterior tibialvein and artery travel adjacent to the tibial nerve from the knee to thefoot. One or more leads 265 can be constructed and arranged to utilizeany of these locations to transvascularly stimulate the tibial nerve(e.g. transvascularly stimulate the tibial nerve via the poplitealartery, popliteal vein, saphenous vein, posterior tibial artery and/orposterior tibial vein via a lead 265 advanced via the femoral veinand/or artery). In these transvascular embodiments, the housing 210 canbe placed near the femoral or popliteal access point at locations in thegroin, perineum, scrotum, pelvis, hip, thigh, leg, behind the knee,buttocks, abdomen and/or low back. In the case of sacral nervestimulation, one or more leads 265 can be inserted through anincision(s) made in the lower back, such that one or more stimulationelements 260 are positioned proximate (e.g. in contact) with the sacralnerve root(s). The housing 210 can be placed anywhere in the groin,perineum, scrotum, pelvis, hip, thigh, leg, behind the knee, buttocks,abdomen and/or low back. Lead 265 (e.g. a lead 265 comprising a leadextension) can be extended underneath the skin (e.g. tunneled) to asecond incision (e.g. across the flank to the lower abdomen, across themidline to the buttocks, or low back), and a third incision can be made(e.g. in the abdomen, back or buttocks) where housing 210 can beinserted and connected to lead 265. Alternatively, housing 210 can beinserted at another internal location. If lead 265 is already connected(e.g. attached in manufacturing) to housing 210, lead 265 can beadvanced in the opposite direction, such as from the third incision, tothe second incision, to the first incision (if three incisions aremade), or housing 210 can be advanced under the tissue from incision 1to incision 2 or from incision 2 to incision 3. In some embodiments,only 1 or 2 incisions are performed. In some embodiments, such as whenlead 265 is already connected (e.g. attached in manufacturing) tohousing 210, lead 265 and housing 210 are implanted. In someembodiments, a first lead 265 and a first housing 210 (pre-attached orattachable) are utilized in a dose titration or other “trialingprocedure”, and a second lead 265 and housing 210 (pre-attached orattachable) are implanted in the patient for subsequent treatment of thepatient.

In some embodiments, one or more stimulation elements 260 are positionedto perform posterior tibial nerve stimulation (PTNS), such as to performan indirect form of neuromodulation to treat bladder voidingdysfunction. The posterior tibial nerve is derived from thelumbar-sacral nerves (L4-S3), which innervate the bladder detrusor andpelvic floor. In some embodiments, one or more stimulation elements 260are positioned to perform retrograde stimulation of the sacral nerveplexus and restore the balance between bladder inhibitory and excitatorycontrol systems of the bladder. One or more stimulation elements 260 canbe positioned above the ankle, proximate and/or into the tibial nerve.Implantable device 200 can deliver stimulation energy to the stimulationelements 260 comprising low-voltage electrical stimulation configured toproduce sensor and/or motor responses. Apparatus 10 can be configured toprovide continuous and/or intermittent stimulation to tissue, such as tomodulate transmission of excitatory nerve signals to the bladdermuscles. In some embodiments, implantable system 20 is configured todeliver a series of repeated stimulation periods, such as a regimen ofapproximately: weekly thirty-minute sessions of stimulation for twelveweeks. In some embodiments, implantable system 20 is configured toprovide weekly, daily and/or hourly sessions that deliver stimulationfor between 10 minutes and 60 minutes. Implantable system 20 can deliverstimulation for any number of minutes per day. In some embodiments,apparatus 10 is configured to achieve an approximate 50% reduction inurinary urge incontinence and/or urinary urgency/frequency episodes.

In some embodiments, apparatus 10 is configured to provide temporarystimulation of tissue to treat overactive bladder, such as by usingtrialing interface 80 and/or 90 described hereabove, such as to providepower and/or data to one or more implantable devices 200 to confirmacceptable improvement of the patient's overactive bladder (e.g.successful stimulation of one or more sacral nerves, tibial nerves orother tissue), before closing an incision or otherwise fully implantingone or more implantable devices 200. In some embodiments, a temporarystimulation (for overactive bladder or in a trialing procedure for anytherapy) is provided for up to one week, up to one month, more than 1month, more than 2 months, or more than 3 months. In some embodiments,one or more implantable devices 200 are left in place if the temporarystimulation period is successful or unsuccessful (e.g. left implanteddue to its small size or otherwise minimal impact on the patient).

In some embodiments, apparatus 10 is configured to stimulate a region ofthe pelvic floor, such as to: change the reflex thresholds of thebladder muscles responsible for bladder emptying, strengthen and/orotherwise improve the condition of the muscles that maintain closure onthe bladder outlet; change the state of the neural pathways, musculatureand/or bladder during and beyond the period stimulation; and/orotherwise decrease the severity of urinary incontinence. In someembodiments, one or more stimulation elements 260 are positioned tostimulate periurethral muscles. In some embodiments, one or morestimulation elements 260 are positioned to stimulate tissue of thevagina or anus. In some embodiments, one or more stimulation elements260 are positioned to stimulate sphincter muscles for controlling thebladder, such as two stimulation elements 260 positioned on either sideof the urethral orifice. In these embodiments, housing 210 can beimplanted in suprapubic region or in the perineum. In some embodiments,lead 265 comprises (e.g. on a distal portion) a pessary ring comprisingtwo stimulation elements 260. In some embodiments, stimulation elements260 comprise periurethral electrodes configured to stimulate pudendalafferents.

As described above, apparatus 10 can be configured for treating numerousdiseases, disorders or other undesirable patient conditions, such asfecal incontinence. Injury of nerves that sense stool in the rectum canlead to fecal incontinence. In some embodiments, one or more stimulationelements 260 (e.g. one or more electrical, magnetic, light or otherenergy delivery elements) of one or more leads 265 and/or one or moreimplantable devices 200 are configured to stimulate tissue to treatfecal incontinence, such as to treat tissue selected from the groupconsisting of: sacral nerve tissue; tissue whose stimulation strengthensmuscles of the bowel and/or rectum; and combinations of one or more ofthese. In these fecal incontinence applications, leads 265 can beimplanted in a location selected from the group consisting of: thepelvic girdle; the sacral foramina; the lower back; the upper buttock;and combinations of one or more of these, such as to stimulate sacralnerve tissue. Leads 265 can be anchored via lead anchors (silicone orother materials), suture, staples, clips, adhesive and the like, such asan attachment to the underlying fascia of target tissue to bestimulated. In some embodiments, apparatus 10 is configured to treatboth fecal incontinence and a bladder disorder such as overactivebladder, such as when one or more stimulation elements 260 areconfigured to deliver energy to sacral nerve or other tissue.

In some embodiments, apparatus 10 is configured to treat fecalincontinence, overactive bladder (i.e. overactive bladder and/or urinaryincontinence), and/or pelvic disorders, and implantable device 200:comprises between 1 and 16 stimulation elements 260, such as four ormore electrodes; delivers electrical stimulation energy at a range ofapproximately between 10 Hz and 15 Hz (or a range of between 5 Hz and 25Hz); delivers electrical stimulation energy with a pulse width ofapproximately between 180 μsec and 240 μsec (or between 1 μsec and 200μsec); provides electrical stimulation energy with an amplitude ofapproximately 0.1V to 8.5V (e.g. providing a current between 0.1 mA to10 mA, which can be adjusted in increments between 0.01 mA and 0.1 mA),such as an amplitude between 0.4V and 2.0V; delivers continuouselectrical stimulation energy; delivers intermittent electricalstimulation energy, such as with a period between 8 seconds and 24seconds and/or an on time between 8 seconds and 16 seconds; or an ontime of several hours followed by an off time of several hours (such as8 hours of stimulation ON and 16 hours of stimulation OFF or 16 hours onand 8 hours off, and 12 hour on and 12 hours off; delivers monopolarelectrical energy; delivers bipolar electrical energy; and combinationsof one or more of these.

In some embodiments, apparatus 10 is configured to treat an occipitalneuralgia, such as migraine headache, headache and/or cluster headache,and one or more stimulation elements 260 (e.g. small column paddleelectrodes, standard paddle electrodes or other electrodes) arepositioned to stimulate nerve tissue selected from the group consistingof: occipital; supraorbital; infraorbital; greater occipital nerve(GON); lesser occipital nerve (LON); both supraorbital and GON;supratroclear; sphenopalantine (SPG); and combinations of one or more ofthese.

In some embodiments, apparatus 10 is configured to treat neuralgia, suchas a neuralgia resulting from surgery (e.g. groin, shoulder, lung and/oramputation), trauma and/or phantom pain, and one or more stimulationelements 260 are positioned to stimulate nerve tissue.

In some embodiments, apparatus 10 is configured to treat neuralgia, suchas a neuralgia resulting from groin surgery (e.g. hernia or other groinsurgery), and one or more stimulation elements 260 are positioned tostimulate nerve tissue selected from the group consisting of:ilioinguinal; genitofemoral; iliohypogastric; and combinations of one ormore of these.

In some embodiments, apparatus 10 is configured to treat neuralgia, suchas a neuralgia resulting from shoulder surgery, and one or morestimulation elements 260 are positioned to stimulate axial nerve tissue(e.g. one or more stimulation elements 260 positioned on a lead 265implanted in a suprascapular location).

In some embodiments, apparatus 10 is configured to treat neuralgia, suchas a neuralgia resulting from lung surgery, and one or more stimulationelements 260 are positioned to stimulate intercostal nerve tissue.

In some embodiments, apparatus 10 is configured to treat neuralgia, suchas a neuralgia associated with carpal tunnel syndrome, and one or morestimulation elements 260 are positioned to stimulate median nervetissue.

In some embodiments, apparatus 10 is configured to treat neuralgia, suchas a neuralgia associated with temporomandibular joint disorder (TMJ),and one or more stimulation elements 260 are positioned to stimulate V2of trigeminal nerve tissue.

In some embodiments, apparatus 10 is configured to treat neuralgia, suchas a facial neuralgia, and one or more stimulation elements 260 arepositioned to stimulate trigeminal nerve tissue.

In some embodiments, apparatus 10 is configured to treat neuralgia, suchas a leg (sciatic) neuralgia, and one or more stimulation elements 260are positioned to stimulate nerve tissue proximal a contributing lesion.

In some embodiments, apparatus 10 is configured to treat pelvic pain,such as interstitial cystitis and/or bladder pain, and one or morestimulation elements 260 are positioned to stimulate peripheral nervoussystem tissue (e.g. pudendal tissue and/or S-2, S-3 and/or S-4 roots)and/or central nervous system tissue (e.g. lower spinal cord and/or S3neural foramen).

In some embodiments, apparatus 10 is configured to treat pelvic pain,such as anal pain, and one or more stimulation elements 260 arepositioned to stimulate peripheral nerve tissue such as pudendal tissueand/or S-2, S-3 and/or S-4 roots.

In some embodiments, apparatus 10 is configured to treat subcutaneouspain, and one or more stimulation elements 260 (e.g. paddle electrodes)are positioned to stimulate nerve tissue.

In some embodiments, apparatus 10 is configured to treat diabeticneuropathy, such as painful diabetic neuropathy, and one or morestimulation elements 260 are positioned proximate the lower spinal cord(e.g. to stimulate S3 nerves) or other body location to stimulate nervetissue.

In some embodiments, apparatus 10 is configured to treat visceral pain,angina and/or other pain, and one or more stimulation elements 260 arepositioned to stimulate the vagus nerve.

In some embodiments, apparatus 10 is configured to treat peripheralvascular disease, diabetic neuropathy and/or other conditions associatedwith diabetes, such as to treat a disease or disorder selected from thegroup consisting of: peripheral diabetic neuropathic pain; painfuldiabetic peripheral neuropathy; peripheral vascular disease; peripheralarterial disease; peripheral artery disease; cardiac autonomicneuropathy; diabetic autonomic neuropathy; diabetic sensory neuropathy;diabetic motor neuropathy; diabetic sensorimotor neuropathy; diabeticmuscular atrophy; diabetic neurovascular disease; and combinations ofone or more of these. In these embodiments, lead 265 can be positionedproximate a nerve in the foot, leg, arm and/or sacrum (e.g. such thatone or more stimulation elements 260 are positioned proximate the nerveto be stimulated). In some embodiments, lead 265 is positioned tostimulate the dorsal root ganglia to treat diabetic neuropathy (e.g.diabetic neuropathy of the hand and/or foot). Lead 265 can be implantedpercutaneously and/or surgically as described herein. Lead 265 and/orone or more stimulation elements 260 can comprise a paddle electrode,such as one or more paddle electrodes implanted in the foot, leg and/orarm. Lead 265 and/or one or more stimulation elements 260 can comprise acuff or hemi-cuff electrode surgically implanted around a nerve in thefoot, leg and/or arm. Apparatus 10 can be configured to provide spinalcord stimulation, either through percutaneous insertion of one or moreleads 265 in the epidural space or surgical implantation of a lead 265comprising a paddle lead positioned in the epidural space. Apparatus 10can be configured to provide transvascular stimulation of nerves in thefoot, leg and/or arm, (e.g. to treat diabetic neuropathy) such as whenone or more leads 265 are interventionally advanced into the venous orarterial system. Leads 265 can be positioned using percutaneoustransforaminal placement in the sacral foramina, such as for treatmentof foot or leg disorders. Leads 265 can be constructed and arranged forcephalocaudal insertion (retrograde) into the epidural space or sacralcanal, such as for treatment of foot or leg disorders. Leads 265 can beconstructed and arranged to provide dorsal root ganglion stimulation,such as for treatment of trunk, neck, head, back, foot, leg, arm and/orhand disorders.

One or more leads 265 (e.g. each including one or more stimulationelements 260) can be constructed and arranged to stimulate tibial nervefibers, such as to treat diabetic neuropathy and/or diabetic relatedmaladies of the foot. The tibial nerve can be accessed as describedherein.

One or more leads 265 can be configured to stimulate the peroneal nerveor saphenous nerve, such as at one or more locations describedherebelow. The peroneal nerve can be accessed percutaneously orsurgically behind the knee in the popliteal fossa where it branches offthe sciatic nerve. It can also be accessed as it wraps around thelateral aspect of the knee just prior to diving under the fibularislongus and extensor digitorum longus muscles. The deep fibular nerve (abranch of the peroneal nerve) innervates top medial foot, whereas thesuperficial fibular (peroneal) innervates top of both medial and lateralfoot. In some embodiments, stimulation element 260 comprises one or moreelectrodes positioned in the anterior tibial vein and/or artery totransvascularly stimulate the deep fibular nerve. The saphenous nervecomes off the femoral nerve deep in the thigh. It passes around themedial aspect of the knee medial to the patella. It then runs down themedial shin adjacent to the tibia, gastrocnemius and soleus muscleswhere it can be accessed surgically or percutaneously. It then surfacesjust as it warps around the anterior aspect of the medial malleoluswhere it supplies the medial posterior foot in front of heel. The medialsural cutaneous nerve comes off the tibial at the popliteal fossa, thenruns down the back of the calf (over the gastrocnemius) and wraps aroundthe posterior aspect of the lateral malleolus before innervating thelateral aspect of the sole and heel. In some embodiments, the saphenousnerve is transvascularly stimulated by positioning one or morestimulation elements 260 in a blood vessel selected from the groupconsisting of: femoral vein; femoral artery; great saphenous vein; greatsaphenous artery; and combinations of one or more of these. In someembodiments, the sural nerve is stimulated. In these embodiments, thesural nerve can be transvascularly stimulated by positioning one or morestimulation elements 260 in the saphenous vein.

One or more leads 265 can be configured to stimulate the median nerve,ulnar nerve and/or radial nerve. The median nerve can be accessedpercutaneously in the upper arm lateral to the brachial vein and/orartery, but medial to the biceps muscle, whereas the ulnar nerve runsmedial to the brachial artery in the upper arm. The median nerve passesthrough the anterior aspect of the elbow under the bicipitalaponeurosis. The ulnar nerve runs medial and posterior to the medialepicondyle of the humerus. The median nerve can also be accessed in thewrist just proximal to the palm and the palmar carpal ligament. Theulnar nerve can be accessed just proximal to the palmar carpal ligamentadjacent to the pisiform. The radial nerve can be accessedpercutaneously just as it passes anterior to the lateral epicondyle. Insome embodiments, apparatus 10 is configured to transvascularlystimulate at least one of a median nerve, an ulnar nerve or a radialnerve, and stimulation element 260 comprises one or more electrodespositioned in a vessel selected from the group consisting of: brachialvein; brachial artery; basilic vein; basilic artery; deep vein of thearm; deep artery of the arm; and combinations of one or more of these.In some embodiments, apparatus 10 is configured to transvascularlystimulate at least one of a median nerve or an ulnar nerve, andstimulation element 260 can comprise one or more electrodes positionedin a vessel selected from the group consisting of: brachial vein;brachial artery; and combinations of one or more of these. In someembodiments, apparatus 10 is configured to transvascularly stimulate theradial nerve, and stimulation element 260 comprises one or moreelectrodes positioned in a vessel selected from the group consisting of:deep vein of arm; deep artery of arm; basilic vein; radial collateralvein; radial collateral artery; medial collateral vein; medialcollateral artery; radial vein; radial artery; and combinations of oneor more of these. In some embodiments, apparatus 10 can be configured totransvascularly stimulate the medial cutaneous nerve, and stimulationelement 260 comprises one or more electrodes positioned in the basilicvein. In some embodiments, apparatus 10 is configured to transvascularlystimulate the ulnar nerve, and stimulation element 260 comprises one ormore electrodes positioned in a vessel selected from the groupconsisting of: ulnar collateral vein; ulnar collateral artery; ulnarvein; ulnar artery; and combinations of one or more of these. In someembodiments, apparatus 10 is configured to transvascularly stimulate themedian nerve, and stimulation element 260 can comprise one or moreelectrodes positioned in a vessel selected from the group consisting of:brachial vein; brachial artery; ulnar vein; ulnar artery; andcombinations of one or more of these.

As described herein, one or more leads 265 can be positioned tostimulate the spinal cord, such as via percutaneous insertion of a lead265 in the epidural space or surgical implantation of the lead 265 (e.g.a paddle lead) in the epidural space. A lead 265 can be placed such thatone or more stimulation elements 260 (e.g. one or more electrodes) arepositioned from T5-S5, such as to capture the area of pain or reducedcirculation of the leg or foot. One or more stimulation elements 260 ofone or more leads 265 can be positioned from C2 to T8, such as tocapture the area of pain or reduced circulation of the arm or hand. Oneor more leads 265 can be placed along the midline, unilaterally and/orbilaterally over the dorsal columns, in the gutter (over dorsal roots)and/or in the dorsal root entry zone. Leads 265 can span severalvertebral levels or they can be positioned to span a single level.

One or more stimulation elements 260 (e.g. one or more electrodesattached to one or more leads 265) can be positioned to transvascularlystimulate one or more nerves, such as one or more nerves in the foot,leg and/or arm, such as when the one or more stimulation elements 260are implanted within one or more blood vessels of the venous and/orarterial system.

In the leg, the tibial nerve, sacral roots and/or deep fibular nerve canbe stimulated, such as when a lead 265 accesses the tissue to bestimulated through a transvascular approach, such as via the femoralvein and/or artery, as described herein. The deep fibular nerve can bestimulated by one or more stimulation elements 260 positioned in theanterior tibial vein and/or the anterior tibial artery. In the arm, themedian nerve, ulnar nerve, superior ulnar nerve, medial cutaneous nerveand/or radial nerve can be stimulated, such as when lead 265 accessesthe tissue to be stimulated through a transvascular approach, such asvia the brachial vein and/or artery, the basilic vein and/or artery,and/or the deep vein and/or artery.

One or more stimulation elements 260 (e.g. one or more electrodesattached to one or more leads 265) can be positioned to stimulate dorsalroot ganglia that supply the following nerves (e.g. to treat the legand/or foot): common peroneal (L4-S2); tibial (L4-S3); femoral (L2-L4);and combinations of one or more of these. One or more stimulationelements 260 (e.g. one or more electrodes attached to one or more leads265) can be positioned to stimulate dorsal root ganglia that supply thefollowing nerves (e.g. to treat the hand and/or arm): radial (C5-T1);median (C5-T1); ulnar (C7-T1); and combinations of one or more of these.In these embodiments, one or more leads 265 can be passed through theintervertebral foramina, either unilaterally or bilaterally, at a singlevertebral level or at multiple vertebral levels.

In some embodiments, apparatus 10 is configured to treat post-amputationpain, such as to treat a disease or disorder selected from the groupconsisting of: phantom limb pain; phantom stump pain; acute andpersistent stump pain; limb pain; neuroma; Morton's neuroma;neurilemoma; neurolemoma; Schwann cell tumor; phantom limb itch; phantomlimb sensations; and combinations of one or more of these. Apparatus 10can be configured to treat the conditions associated withpost-amputation pain (i.e., stump pain), such as by using a highfrequency alternating current (HFAC) block approaches. In theseembodiments, one or more leads 265 can be implanted such that one ormore stimulation elements 260 stimulate one or more nerves in the leg,arm and/or sacrum. One or more leads 265 can be surgically implanted,such as when lead 265 comprises a paddle electrode positioned near anerve in the foot, leg or arm and/or a cuff electrode or hemi-cuffelectrode positioned to at least partially surround a nerve in the foot,leg or arm. One or more leads 265 can be positioned to stimulate thespinal cord, such as via a percutaneous insertion of the leads 265 inthe epidural space or surgical implantation of the lead 265 (e.g. apaddle lead) in the epidural space. One or more leads 265 can bepositioned to provide transvascular stimulation of nerves in the leg orarm, such as when one or more stimulation elements 260 are implantedwithin a vein or artery. One or more leads 265 can be implanted usingpercutaneous transforaminal placement in the sacral foramina, such asfor treatment of leg stump pain. One or more leads 265 can be implantedusing cephalocaudal insertion (retrograde) into the epidural space orsacral canal, such as for treatment of leg stump pain. One or more leads265 can be positioned to perform dorsal root ganglion stimulation and/orblock, such as for treatment of leg and/or arm stump pain.

In some embodiments, apparatus 10 is configured to treat occipitaland/or headache (HA) pain, such as when apparatus 10 is configured totreat a disease or disorder selected from the group consisting of:occipital neuralgia; cervicogenic headache; tension headache; chronicand episodic migraine headache; tension headache; hemicrania continua;trigeminal autonomic cephalalgias (TACs); chronic and episodic clusterheadache; chronic and episodic paroxysmal hemicranias; short-lastingunilateral neuralgiform headache attacks with conjunctival injection andtearing (SUNCT); short-lasting unilateral neuralgiform headache attackswith cranial autonomic symptoms (SUNA); long-lasting autonomic symptomswith hemicrania (LASH); post-traumatic headache; and combinations of oneor more of these.

Apparatus 10 can be configured to treat the conditions associated withheadache pain and/or occipital neuralgia by stimulating one or morenerves in the head, such as one or more nerves selected from the groupconsisting of: greater and/or lesser occipital nerve (e.g. which arisefrom C2 and C3); the greater and/or lesser auricular nerves (e.g. whichalso arise from C2/C3); the third (least) occipital nerve (e.g. whicharises from C3); and combinations of one or more of these. Theinfraorbital or supraorbital nerves can be access subcutaneously belowand above the eye, respectively. Apparatus 10 can be configured tostimulate auriculotemporal, supratrochlear and/or sub-occipital nerves.To stimulate any of these nerves, lead 265 (e.g. a cylindrical SCS-typelead) can be inserted percutaneously either subcutaneously or under themuscle. Alternatively, surgery (e.g. direct cut-down) can be performedto insert lead 265 (e.g. a cylindrical lead, a paddle lead, a cuff orhemi-cuff electrode) proximate, one and/or around these nerves.Alternatively or additionally, the nerves can be accessedtransvascularly as described herein (e.g. when one or more stimulationelements 260 are implanted in a blood vessel). Housing 210 can beimplanted anywhere in the head under the skin, including: behind theear, back of the head, the neck, in the face, and the like, where one ormore external devices 500 can be positioned in, on and/or within a hat,headband, glasses, goggles, earpiece, necklace, patch, and the like.Apparatus 10 can be configured to treat headache pain and/or occipitalneuralgia by stimulating tissue in the cervical spinal cord (C2-C3), forexample proximate the location the nerve enters the cord from theforamen. One or more leads 265 can be placed over the dorsal columns, inthe gutter, over the dorsal root entry zone and/or out in the foramen atthe dorsal root ganglion. In some embodiments, the trigeminal andpterygopalatine ganglia are accessed by inserting one or more leads 265through the face or the roof of the mouth. In these embodiments, housing210 can be placed anywhere in the head under the skin, as describedherein.

In some embodiments, apparatus 10 is configured to treat post-herpeticneuralgia, such as to treat a disease or disorder selected from thegroup consisting of: shingles; herpes zoster; zoster; zona; varicellazoster virus infection; zoster sine herpete; fever blisters; herpeszoster blisters; herpes zoster rash; and combinations of one or more ofthese. In some embodiments, apparatus 10 is configured to treatpost-herpetic neuralgia using high frequency alternating current (HFAC)block approaches. In these embodiments, one or more leads 265 can beimplanted such that one or more stimulation elements 260 stimulate oneor more nerves in the leg, arm, torso and/or sacrum. One or more leads265 can be surgically implanted, such as when lead 265 comprises apaddle electrode positioned near a nerve in the foot, leg, torso and/orarm and/or a cuff electrode or hemi-cuff electrode positioned to atleast partially surround a nerve in the foot, leg, torso or arm. One ormore leads 265 can be positioned to stimulate the spinal cord, such asvia a percutaneous insertion of the leads 265 in the epidural space orsurgical implantation of the lead 265 (e.g. a paddle lead) in theepidural space. One or more leads 265 can be positioned to providetransvascular stimulation of nerves in the leg, torso and/or arm, suchas when one or more stimulation elements 260 are implanted within a veinor artery. One or more leads 265 can be implanted using percutaneoustransforaminal placement in the sacral foramina, such as for treatmentof leg or foot pain. One or more leads 265 can be implanted usingcephalocaudal insertion (retrograde) into the epidural space or sacralcanal, such as for treatment of leg or foot pain. One or more leads 265can be positioned to perform dorsal root ganglion stimulation and/orblock, such as for treatment of leg, torso and/or arm pain.

In some embodiments, apparatus 10 is configured to treat angina, such asto treat a disease or disorder selected from the group consisting of:angina; chest pain caused by reduced blood flow to the heart muscle;chest pain associated with coronary artery disease such as squeezing,pressure, heaviness, tightness or pain in the chest; recurring anginapectoris; acute angina pectoris; chronic angina pectoris; acute coronarysyndrome; chest pain; coronary artery spasms; microvascular angina;Prinzmetal's angina; angina inversa; stable or common angina; unstableangina; variant angina; and combinations of one or more of these.

In some embodiments, apparatus 10 is configured to treat carpal tunnelsyndrome, such as to treat a disease or disorder selected from the groupconsisting of: median nerve entrapment; tingling and/or numbness infingers or hand; median nerve irritation or compression; narrowing ofthe carpal tunnel; and combinations of one or more of these. In theseembodiments, apparatus 10 can be configured to deliver stimulation tomedian nerve tissue; ulnar nerve tissue and/or radial nerve tissue.

In some embodiments, apparatus 10 is configured to treat erectiledysfunction (ED), such as to treat a disease or disorder selected fromthe group consisting of: impotence; male sexual dysfunction; inabilityto develop or maintain an erect penis; cardiogenic ED; vasculogenic ED;diabetic ED; neurogenic ED; traumatic ED; post-prostatectomy ED;hormonal ED; hyopogonadism; pharmacological ED; and combinations of oneor more of these.

In some embodiments, apparatus 10 is configured to treat complexregional pain syndrome (CRPS), such as to treat a disease or disorderselected from the group consisting of: CRPS type 1; CRPS type 2; reflexsympathetic dystrophy; causalgia; reflex neurovascular dystrophy;amplified musculoskeletal pain syndrome; systemic autonomicdysregulation; neurogenic edema; musculoskeletal pain; and combinationsof one or more of these.

In some embodiments, apparatus 10 is configured to treat knee pain. Kneepain from joint degeneration or join replacement surgery can be treatedvia stimulation of the nerves innervating the knee and/or viastimulation of the tissue surrounding the knee (sometimes referred to asperipheral field stimulation). Apparatus 10 can comprise between one andeight leads 265 whose stimulation elements 260 are placed near andaround the knee. In some embodiments, four leads 265 are placed, inlocations medial, lateral, superior and inferior to the knee. The leads265 can be placed subcutaneously for field stimulation, or they can beplaced directly adjacent to specific nerve targets. Applicable nervetargets are as follows: medial knee can include medial femoral cutaneousand infrapatellar cutaneous branches of saphenous nerve; lateral kneecan include constant articular branches of common peroneal, lateralretinacular nerve; anterior knee can include lateral, medial, andanterior cutaneous femoral nerve, infrapatellar branch of saphenousnerve, medial and lateral retinacular nerve and articular branches ofperoneal nerve; posterior knee can include obturator, posterior tibialand sciatic nerves. In addition, the following nerves can be stimulatedvia stimulation elements 260 to treat knee pain: nerves arising from thetibial nerve such as the superior, middle and inferior genicular nerves;nerves arising from the common peroneal such as the superior lateral,inferior lateral, and recurrent genicular nerves; and nerves arisingfrom the obturator nerve such as the genicular branch of obturator; andnerves arising from the femoral nerve such as the saphenous nerve. Eachof these targets can be stimulated transvascularly by one or morestimulation elements 260.

In some embodiments, implantable device 200 has an internal battery orother power supply such that stimulation (e.g. stimulation energy and/ora stimulation agent) is delivered to one or more locations within apatient for an extended time period (e.g. at least 1 hour, at least 1day, at least 1 month or at least 1 year), without receiving a powertransmission (e.g. as described herein from an external device such asexternal device 500) during that time period. In some embodiments, atleast a portion of a single pulse of energy (e.g. at least a singlephase) is delivered by implantable device 200 using energy provided byan internal power supply 570 such as a battery or a capacitor. In theseembodiments, data can be transmitted by one or more of an externaldevice 500 and/or a programmer 600, such as to activate or modifystimulation being delivered, with or without also transmitting power.

In some embodiments, implantable device 200 comprises one or morecomponents configured to receive transmitted power (e.g. via an externaldevice 500), receive transmitted data (e.g. via an external device 500and/or programmer 600) and/or deliver stimulation (e.g. deliverstimulation energy and/or a stimulation agent).

In some embodiments, one or more implantable devices 200 are configuredto deliver stimulation energy (e.g. via one or more stimulation elements260 comprising an electrode) with a stimulation waveform comprising oneor more high frequency signals (e.g. a signal comprising one or morehigh frequency components). For example, one or more implantable devices200 can deliver one or more stimulation waveforms comprising one or moresignals above 600 Hz, such as one or more signals above 1.0 kHz, 1.2kHz, 5 kHz, 10 kHz or 25 kHz.

In these embodiments, the delivered stimulation waveform can beconfigured to be void of (i.e. not include) one or more lower frequencysignals, such as by not including any signals at a frequency below 100Hz, below 500 Hz, below 1000 Hz, below 1200 Hz or below 1500 Hz.

One or more implantable devices 200 can be configured to deliverstimulation energy with a stimulation waveform that varies over time. Insome embodiments, one or more stimulation parameters of the stimulationwaveform are randomly varied over time, such as by using a probabilitydistribution as described in applicant's co-pending U.S. patentapplication Ser. No. 16/104,829, titled “Apparatus with EnhancedStimulation Waveforms”, filed Aug. 17, 2018 [Docket nos. 47476-708.301;NAL-014-US]. Each stimulation waveform can comprise one or more pulses,such as a group of pulses that are repeated at regular and/or irregularintervals. In some embodiments, a pulse can comprise delivery ofelectrical energy, such as electrical energy delivered in one or morephases (e.g. a pulse comprising at least a cathodic or anodic portionfollowed by passive capacitive recovery with an optional open circuittime between the first portion and recovery). In some embodiments, agroup of pulses is delivered, each pulse comprising an anodic orcathodic portion that can include charge recovery after each pulse, suchas charge recovery comprising active (opposite polarity pulse) recovery,and/or passive (capacitive) recovery. In some embodiments, there is norecovery between pulses, but instead active or passive recovery isincluded at the end of the set of the first (anodic or cathodic)portions. In some embodiments, single or groups of pulses are providedat time-varying modes of repetition (e.g. regular intervals for aperiod, then a period of irregular intervals) or at regular intervalswith occasional (random) spurious pulses inserted (creating a singleirregular event in an otherwise regular series). Non-limiting examplesof waveform variations include: a variation in frequency (e.g. frequencyof one or more signals of the waveform); variation of a signalamplitude; variation of interval time period (e.g. at time periodbetween pulses or a time period between pulse trains); variation of apulse width; multiple piecewise or continuous variations of one of morestimulation parameters in a single pulse (e.g. multi-step,multi-amplitude in one “super-pulse”); variation of pulse symmetry (e.g.via active drive, passive recovery and/or active-assisted passiverecovery); variation of stimulation energy over a time window and/oroverlapping time windows; variation of the power in the frequencyspectrum of the stimulation waveform; and combinations of one or more ofthese. In some embodiments, apparatus 10 and/or implantable device 200can be configured to vary a stimulation waveform “systematically” suchas a variation performed temporally (e.g. on predetermined similar ordissimilar time intervals) and/or a variation performed based on aparameter, such as a measured parameter that can be based on a signalproduced by a sensor of implantable device 200 or another component ofapparatus 10. Alternatively or additionally, apparatus 10 and/orimplantable device 200 can be configured to vary a stimulation waveformrandomly. Random variation shall include discrete or continuousvariations that can be selected from a distribution, such as aprobability distribution selected from the group consisting of: auniform distribution; an arbitrary distribution; a gamma distribution; anormal distribution; a log-normal distribution; a Pareto distribution; aGaussian distribution; a Poisson distribution; a Rayleigh distribution;a triangular distribution; a statistic distribution; and combinations ofone or more of these. Random pulses or groups of pulses can be generatedbased on randomly varying one or more stimulation signal parameters. Oneor more stimulation parameters can be varied randomly through the use ofone or more probability distributions, as described herebelow.

In some embodiments, the amplitude of a signal delivered by one or moreimplantable devices 200 is adjusted to prevent discomfort to the patient(e.g. paresthesia or other undesired condition) from the stimulationsignal. In some embodiments, the amplitude of the stimulation signal canbe ramped (e.g. up and/or down), a single time or multiple times (e.g.continuously or intermittently). In some embodiments, a titrationprocedure is performed to “set” one or more stimulation parameters basedon avoiding patient discomfort.

In some embodiments, one or more implantable devices 200 are configuredto deliver stimulation energy (e.g. via one or more stimulation elements260 comprising an electrode) with a stimulation waveform comprising oneor more waveform patterns. The stimulation waveforms delivered can beconfigured to treat various conditions of a patient. Each stimulationwaveform can comprise a series of continuous pulses, intermittentpulses, and/or spurious pulses (e.g. occasional events in an otherwisecontinuous stream). Each pulse can comprise a pulse train that isrepeatedly delivered by implantable device 200, the train comprising oneor more cathodic pulses and/or one or more anodic pulses. In someembodiments, implantable device 200 delivers a multiphasic pulsecomprising at least two cathodic pulses and/or anodic pulses, with orwithout any time between each pulse. For example, implantable device 200can deliver a biphasic pulse comprising a cathodic pulse followed by ananodic pulse, a triphasic pulse comprising a cathodic pulse followed byan anodic pulse followed by a second cathodic pulse, or any series oftwo or more cathodic and/or anodic pulses. In some embodiments,delivered pulses are exponential in nature (e.g. comprise an exponentialportion), such as dynamic return pulses that exceed a minimum current(e.g. at least 1 mA, 10 mA or 50 mA) for a short duration (e.g. forapproximately 1 μsec), and then decay to lower current levels (e.g. alevel of approximately 100 nA), with a time constant on the order of 1μsec to 100 μsec.

The stimulation waveforms delivered by implantable device 200 cancomprise one or more high frequencies. The stimulation waveformfrequency or other stimulation parameter can be set and/or adjusted(hereinafter “adjusted”) to optimize therapeutic benefit to the patientand minimize undesired effects (e.g. paresthesia or other patientdiscomfort). In some embodiments, a stimulation waveform is adjustedbased on a signal produced by a sensor of apparatus 10 (e.g. a sensor ofimplantable device 200, such as a stimulation element 260 configured asa sensor or other sensor of implantable device 200 as describedhereabove). Adjustment of a stimulation waveform parameter can beperformed automatically by the implantable device 200 and/or via anexternal device 500 and/or programmer 600).

In some embodiments, a pulse shape of a stimulation waveform can bevaried, such as a pulse shape comprising: a sinusoidal geometry; asquare geometry (e.g. a waveform comprising a square wave); arectangular geometry; a triangular geometry; (e.g. symmetric orasymmetric); a trapezoidal geometry; a sawtooth geometry; a rampedgeometry; an exponential geometry; a piece-wise step function geometry;a root-raised cosine geometry; and combinations of one or more of these.

In some embodiments, a charge recovery phase (e.g. anodal phase) of astimulation waveform is varied by implantable device 200.

Inter-pulse gap, the time between one or more pulses (e.g. a biphasic orother multiphasic pulse that is repeated continuously), can be variedsystematically and/or randomly by implantable device 200. In someembodiments, inter-pulse gap between one or more pulses comprises zerotime (i.e. a first pulse is immediately followed by a similar ordissimilar second pulse). In some embodiments, inter-pulse gap is variedsystematically, such as on a routine basis (i.e. temporally) and/orvaried based on a signal produced by a sensor of apparatus 10.Alternatively or additionally, inter-pulse gap can be varied randomly,such as a random variation based on a distribution (e.g. a probabilitydistribution with a pre-determined shape) as described herebelow.

In some embodiments, implantable device 200 delivers a stimulationwaveform comprising a series of frequency modulated (FM) pulses, suchthat the frequency of stimulation varies. Implantable device 200 can beconfigured to deliver a frequency modulated stimulation waveformcomprising a carrier signal, at a carrier frequency, that is modulatedcontinuously between a first frequency and a second frequency. Forexample, implantable device 200 can deliver a stimulation waveform thatmodulates between 2.0 kHz and 3.0 kHz every second (e.g. comprising acarrier signal at 2.5 kHz that is modulated at 1 Hz) with a modulationrange (the excursion from the carrier signal) of +/−500 Hz. In someembodiments, implantable device 200 can deliver a stimulation waveformthat comprises: a carrier frequency between 1 kHz and 50 kHz, amodulation frequency between 0.1 Hz and 10 kHz and/or a modulation rangebetween 1 Hz and the carrier frequency.

In some embodiments, implantable device 200 delivers a stimulationwaveform comprising a series of amplitude modulated (AM) pulses, suchthat the amplitude of stimulation varies (e.g. varying the amplitude ofthe voltage and/or current of the stimulation signal). The amplitude ofdelivered current can be varied in a single amplitude modulated sweep,such as a sweep from 2 mA to 3 mA. In some embodiments, amplitude of asignal can be varied continuously, such as when current is variedbetween 2 mA and 3 mA every second (e.g. a signal comprising amodulation frequency of 1 Hz). In these embodiments, the depth ofmodulation would be 33%, where depth of modulation is equal to 1−[lowerrange/upper range]. In some embodiments, amplitude of delivered currentfluctuates between 1 mA and 3 mA (i.e. a depth of modulation of 66%),while in other embodiments, current fluctuates between 0 mA and 10 mA(e.g. a depth of modulation of 100%). In some embodiments, implantabledevice 200 is configured to deliver an amplitude modulated signalcomprising: a carrier frequency between 1 Khz and 50 kHz; a modulationfrequency between 0.1 Hz and the carrier frequency and/or a depth ofmodulation between 0.1% and 100%.

In some embodiments, implantable device 200 delivers a stimulationwaveform comprising delivery of continuously balanced analog currentwaveforms, for example from a differential Howland current source. Inthese embodiments, there are not independent pulses, but rather there istrue analog frequency and amplitude modulation. Periods of deliveringstimulation (or presence of balanced differential analog stimulation)and periods of no stimulation (e.g. a quiescent period) can be included.In some embodiments, controller 250 comprises one or more reconfigurablestimulation blocks including one or more Howland or other currentsources. The one or more current sources (e.g. two or more currentsources) can each be attached to a stimulation element 260 (e.g. in amonopolar configuration when the current source is also connected tohousing 210 or in a bipolar configuration when the current source isconnected to a pair of stimulation elements 260). Alternatively,controller 250 can comprise one or more current sources that areattached to a matrix of switches that selectively connect the one ormore current sources to multiple stimulation elements 260 (e.g. connecta single current source to 2, 4, 8, 12 or 16 electrodes). In someembodiments, controller 250 is configured such that a stimulationwaveform signal provided to the current source passes through acapacitor (e.g. capacitor C1 shown), the capacitor providing DC balance.

In some embodiments, implantable device 200 delivers a stimulationwaveform comprising delivery of multiple trains of pulses that aredelivered intermittently, a “burst stimulation” waveform as definedhereabove. For example, implantable device 200 can be configured todeliver a series or train of five pulses, each with a 1 msec pulsewidth. The each of the five pulses can be separated by an inter-pulsegap of 4 msec, creating a train-on period of 16 msec. These five pulsescan be repeated every 25 msec (the “inter-train period”). In someembodiments, implantable device 200 can be configured to deliver a burststimulation waveform comprising a pulse width between 5 μsec and 1 msec.Implantable device 200 can deliver a train or burst stimulation waveformcomprising pulses with constant pulse widths and/or varying pulsewidths, such as when the pulse widths (and/or other stimulationparameters) are varied randomly and/or systematically. Implantabledevice 200 can deliver a train or burst stimulation waveform with avaried or constant pulse shape selected from the group consisting of:sinusoid; square, rectangle; triangle (symmetric or asymmetric);trapezoid; sawtooth; ramp (e.g. a linear ramp); exponential curve;piece-wise step function; and combinations of one or more of these.Implantable device 200 can deliver a train or burst stimulation waveformwith an inter-pulse gap less than inter-train period. The inter-pulsegap can be relatively constant, and/or it can be varied, such as whenimplantable device 200 randomly varies the inter-pulse gap or varies theinter-pulse gap systematically. In some embodiments, the inter-pulse gapbetween any two pulses within a pulse train (or burst) can be variedbetween 0.1 μsec and the inter-train period (or inter-burst period).Implantable device 200 can deliver a train stimulation waveform with aninter-pulse gap between 1 μsec and 1 second. Implantable device 200 candeliver a burst stimulation waveform with an inter-train period between1 μsec and 1 second. Implantable device 200 can deliver a burststimulation waveform with an inter-burst period between 20 μsec and 24hours. The inter-burst period can be relatively constant, and/or it canbe varied, such as when implantable device 200 randomly varies theinter-burst period or varies the inter-burst period systematically. Insome embodiments, inter-burst period is varied by the user, such as viaa user using programmer 600. In these embodiments, user activation canbe regulated with one or more safeguards or other limits such as thoseincorporated into patient-controlled analgesia devices. The inter-trainperiod can be varied between 1 μsec and 24 hours. Implantable device 200can deliver a train or burst stimulation waveform with a train-on period(the time between the onset of a first pulse in a pulse train to the endof the last pulse in a pulse train) between 10 μsec and 24 hours. Thetrain-on and/or burst-on period can be relatively constant, and/or itcan be varied, such as when implantable device 200 randomly varies thetrain-on and/or burst-on period or varies the train-on and/or burst-onperiod systematically. Implantable device 200 can deliver a train orburst stimulation waveform with a train or burst envelope selected fromthe group consisting of: cosine; cosine-squared; sine; square;rectangle; triangle (symmetric or asymmetric); trapezoid: sawtooth; ramp(e.g. linear ramp); and combinations of one or more of these.Implantable device 200 can deliver a train and/or burst stimulationwaveform with a train ramp duration or burst ramp duration between 1μsec to 10 minutes. Implantable device 200 can deliver a train and/orburst stimulation waveform with a depth of modulation between trainand/or bursts of between 1% and 99%. For example, between some or all ofthe trains and/or bursts (burst-off or train-off periods), a signal maybe present and may contain the same or different elements contained inthe train-on and/or burst-on period. These burst-off or train-offperiods may comprise a quiescent period. The amplitude of the signalcontained in these quiescent periods can be from 0% to 99% of the signalamplitude during the train-on and/or burst-on period, such as a signalwith an amplitude less than 50% of the signal amplitude during thetrain-on and/or burst-on period or another amplitude below a neuronalexcitation threshold.

In some embodiments, apparatus 10 is configured to deliver stimulationenergy to dorsal root ganglion and/or spinal cord tissue to treat acondition such as pain. In these and other embodiments, apparatus 10 canbe configured to provide a stimulation waveform comprising: acombination of low frequency stimulation (e.g. electrical energycomprising a low frequency signal) and burst stimulation; burststimulation (e.g. burst stimulation alone); a combination of lowfrequency stimulation and high frequency stimulation; a combination oflow frequency stimulation, high frequency stimulation and burststimulation; and combinations of one or more of these. The stimulationenergy provided by apparatus 10 can be delivered to tissue via one ormore stimulation elements 260, such as two or more electrodes whichdeliver similar or dissimilar stimulation waveforms simultaneouslyand/or sequentially. Each of the stimulation waveforms can comprise oneor more pulses comprising an entire phase or at least a portion of aphase at a superthreshold level. Alternatively or additionally, each ofthe stimulation waveforms can comprise one or more pulses comprising anentire phase or at least a portion of a phase at a subthreshold level.

In some embodiments, apparatus 10 is configured to vary one or morestimulation parameters. The stimulation parameters can be varied tooptimize (e.g. balance the benefits of) therapeutic benefit, systemefficiency, stimulation efficiency, avoidance and/or reduction ofparesthesia, and/or reduction of charge.

Referring now to FIG. 2, a flow chart of a method for positioningexternal device 500 on the skin of the patient is illustrated,consistent with the present inventive concepts. Method 2000 of FIG. 2includes multiple steps for placing, orienting (e.g. rotationallyorienting), and/or otherwise positioning (“positioning” herein) externaldevice 500 on or otherwise proximate (“on” or “proximate” herein) theskin of the patient to ensure proper transfer of data and/or power toone or more implantable devices 200 that are positioned under the skinof the patient (e.g. ensure a proper communication link will bemaintained). Method 2000 is described using the various components ofapparatus 10 described herein.

In STEP 2010, one or more implantable devices 200 are implanted in thepatient at an implant location LOC1 (e.g. LOC1 is the location of one ormore implantable antennas 240 of device 200), such as a location underthe skin on the patient's back. After recovery from the implantationprocedure, STEP 2020 is performed in which an external device 500 ispositioned on the patient's skin proximate location LOC1, such as alocation on the skin of the patient's back.

In STEP 2030, apparatus 10 provides feedback regarding the quality ofthe positioning of external device 500. Quality of the external device500 position (e.g. relative to implantable antenna 240) can bedetermined via analysis of test transmissions sent from external device500 to implantable device 200. For example, external device 500 can senda power and/or data transmission, after which implantable device 200sends feedback, such as a received signal strength indicator (RSSI), toexternal device 500 related to the quality of the transmissions (e.g.the “link”). In some embodiments, a “reference” RSSI can be used tocompare a measured signal level to the RSSI reference to determine thequality of the link. The RSSI reference can comprise a reference thatis: determined during a manufacturing process of apparatus 10; based ona characterization of a population of previously manufactured externaldevices 500 and implantable devices; determined over time, duringpatient use of apparatus 10 (e.g. “learned” during actual use of one ormore external devices 500 transmitting power and/or data with one ormore implantable devices 200); and/or determined during a calibrationprocess performed during programming. There can be multiple distinctlink quality levels output by the RSSI, such as via a numeric scale(e.g. 1 through 4). Positioning of external device 500 can be modified(e.g. moved) to increase the determined link quality. In someembodiments, link quality (e.g. due to the position of external device500 relative to antennas 240) can be determined based on an assessmentof the voltage generated by the power system of implantable device 200(e.g. the voltage of rectifier 232), such as when information regardingthis voltage is transmitted from implantable device 200 to externaldevice 500.

In some embodiments, transmission quality (link quality) can bedetermined by measuring power consumption of apparatus 10 (e.g.measuring the power consumption of external device 500), and externaldevice 500 positioning can be optimized (e.g. moved) based on the powerconsumption measurement. For example, each external device 500 caninclude an energy measurement circuit (e.g. a current measurementcircuit) that can be used to determine energy draw (e.g. current draw)of the device 500. By either calibrating at time of programming and/orlearning over time during use (e.g. delivery of therapy to the patient),apparatus 10 can be configured to assess link quality by measuring theenergy used (e.g. current draw).

In some embodiments, apparatus 10 assesses transmission quality by bothmeasuring power consumption as well as using a reference RSSI, such asis described hereabove.

Feedback information of this transmission quality can be provided (e.g.to the patient) by one or more user output components (e.g. analphanumeric screen, a red light/green light, speaker or other audibledevice, and the like). Feedback information can comprise a simple“good/bad” assessment, or a more detailed (e.g. 3 or more level)assessment of external device 500 position quality (e.g. to assessbetter versus worse placement of external device 500). In someembodiments, feedback information related to quality of external device500 placement is indicated by a changing graph (e.g. bar chart) and/or achanging quantity on a display; and/or a changing tone (from a speaker).

In STEP 2040, the feedback information provided is assessed (e.g. by thepatient), and if acceptable, the positioning procedure of Method 2000can be ended. If not acceptable (or if better positioning is desired),STEP 2050 can be performed where external device 500 is repositioned onthe patient's skin, at a different location that is still proximate tolocation LOC1.

STEPS 2030 thru 2050 can be repeated multiple times, such as to comparevarious positions of external device 500 and/or to optimize externaldevice 500 placement.

In some embodiments, external device 500 is positioned on the skin ofthe patient via patient attachment device 70 (e.g. a belt, strap, vest,and/or other attachment device), and positioning (in STEP 2020) and/orrepositioning (in STEP 2050) is performed using patient attachmentdevice 70.

In some embodiments, apparatus 10 can be configured to provide guidancein repositioning of external device 500 (e.g. relative to an implantedimplantable device 200), such as directional guidance (e.g. up, down,left, right, and the like). For example, the user could enterinformation about a first repositioning motion (e.g. directionalinformation provided using programmer 600), and apparatus 10 can usethat information to provide subsequent repositioning guidance (e.g.feedback received from the repositioning performed via Steps 2030-2040).

Referring now to FIGS. 3A-D various views of a patient attachment device70 and an external device 500 are illustrated, consistent with thepresent inventive concepts. FIG. 3A is a perspective view of patientattachment device 70 a. FIG. 3B is a side view of an external device 500inserted into the patient attachment device 70 a. FIG. 3C is aperspective view of the external device 500 inserted into the patientattachment device 70 a. FIG. 3D is a side sectional view of the externaldevice 500 inserted into the patient attachment device 70 a.

Patient attachment device 70 a can be configured to removably attach toexternal device 500, such as to first position patient attachment device70 a on the patient's skin, and subsequently insert external device 500into the skin-attached device 70 a. After a time period (e.g. after atime period of stimulation and/or other use, such as when power supply570 is relatively depleted, and/or pain has been sufficiently reduced),external device 500 can be removed from attachment device 70 a andreplaced with a second (e.g. fully charged) external device 500. Thisreplacement procedure can be repeated numerous times.

Patient attachment device 70 a of FIGS. 3A-D includes a housing, housing71, that includes a retaining portion 72 and an opening 74, as shown.Retaining portion 72 can be sized and arranged to frictionally engage aportion of each external device 500. Housing 71 can comprise a shapethat approximates the shape of at least a portion of an external device500. For example, a contour of housing 71 can approximate a contour of amating surface of external device 500 (e.g. a surface of a portion ofhousing 510 of external device 500). Additionally or alternatively, the“footprint” of attachment device 70 a (i.e. perimeter shape) can matchand/or approximate the “footprint” of housing 510 of external device 500(e.g. a circle as shown).

Opening 74 can be positioned near the center of patient attachmentdevice 70 a, such as to aid the user in positioning patient attachmentdevice 70 a over implantable device 200. For example, the user canpalpate the patient's skin through opening 74 to locate implantabledevice 200 beneath the tissue and position patient attachment device 70a accordingly. Patient attachment device 70 a can include an attachmentelement comprising an adhesive patch, adhesive 75 shown, which can bepositioned on the bottom side of housing 71 (e.g. the side positionedproximate the patient's skin). Alternatively or additionally, patientattachment device 70 a can include a strap, belt or other attachmentelement, such as is described hereabove in reference to patientattachment device 70 of FIG. 1. Adhesive 75 can comprise one or moreopenings, such as opening 76 shown. Opening 76 can be included to allowviewing of the patient's skin through opening 76 (e.g. during and/orafter placement). Opening 76 can be included to limit the amount of skincovered by adhesive 75 and/or covered by housing 71.

Patient attachment device 70 a can be constructed and arranged such thatdevice 70 a can be positioned on the patient by the patient themselves,and the positioning can be done with a single hand (e.g. when thepatient's other hand is used to perform a palpation procedure to locateimplantable device 200 as described herein). Patient attachment device70 a can be attached to the patient in any orientation, since when anexternal device 500 is inserted into patient attachment device 70 a,patient attachment device 70 a applies retention forces that preventdislodgement of external device 500 (e.g. prevent dislodgement due togravity).

In some embodiments, adhesive 75 is configured to be re-activated (e.g.via a washing, cleaning and/or other process) and/or be replaced (e.g.removed and reattached to housing 71). Alternatively or additionally,adhesive 75 can comprise multiple independent, removable layers ofadhesive, which can be sequentially removed to reactivate adhesive 75.In these embodiments, patient attachment device 70 a can be attached tothe patient's skin (e.g. as described herein) for a first time period(e.g. a time period in which one, two, or more external devices 500 areinserted and/or removed). After the first time period, device 70 a canbe removed from the patient's skin, adhesive 75 reactivated and/orreplaced, and device 70 a again positioned on the patient's skin for asecond time period (e.g. a time period in which one, two, or moreexternal devices 500 are inserted and/or removed).

When external device 500 is to be positioned on the patient's back (e.g.when an implantable device 200 is implanted under the skin of thepatient's back), it can be difficult to position external device 500 toensure proper power and data transmission with implantable device 200.Patient attachment device 70 a is configured to simplify attachment ofpatient attachment device 70 a as well as subsequent insertion andremoval of each external device 500 into and out of, respectively,device 70 a.

In some embodiments, external device 500 includes a projection,projection 5101, that mates with opening 74 of device 70 a. Housing 510and projection 5101 of device 500, as well as housing 71 and retainingportion 72 of device 70 a comprise materials of construction and ageometry such as to have external device 500 remain captured by (e.g.secure within) device 70 a, even when external forces are imparted oneither component (e.g. forces encountered during running and/or otherreasonable physical activity). For example, if device 500 begins todisengage due to such a force, retention forces provided by theengagement of the mating portions of device 500 and device 70 a tend toreposition device 500 back into the secure, captured position.

External device 500 can be configured to be relatively water-tight, suchas when external device 500 is constructed and arranged to resistingress of water when submerged 1 meter deep in a tank of water for 30minutes. For example, housing 510 can include one or more portions thatare attached via adhesive, welding, and the like, such as to resistwater ingress. In some embodiments, external device 500 includes one ormore controls 581 (e.g. controls 581 a, 581 b, and 581 c shown in FIG.3C) that are positioned on the external surface of housing 510, andthese controls may be constructed and arranged to be relativelywater-tight, such as at the level described hereabove. In someembodiments, controls 581 comprise one or more controls that aremanufactured using in-mold decorating (IMD) technology, where a flexibleprinted plastic film applique is utilized with rigid substrate insertmolding. Control 581 can comprise one or more switches or other controlscomprising an engagement surface (e.g. a membrane that is pressed by afinger of the patient to activate control 581) that is continuous withhousing 510, such as to avoid a gap between housing 510 and control 581.In some embodiments, a water-tight design of external device 500comprises a housing 510 including at least a portion with a sufficientlythin wall thickness to allow flexing sufficient such that a user (e.g. auser's finger) can flex the housing and activate a mechanical switchpositioned within housing 510 proximate the flexible portion.Alternatively or additionally, a water-tight design of external device500 can comprise a housing 510 including one or more holes into which amechanical switch can be inserted or accessed (e.g. via a finger of auser) combined with a water-tight overmold (e.g. silicone overmold)positioned over at least a portion of the housing 510 (e.g. over atleast the holes in housing 510).

Referring now to FIGS. 4A-B, perspective views of an electronic assemblyof implantable device 200 are shown, consistent with the presentinventive concepts. In FIG. 4A, electronic assembly 255 is shown in anunfolded state, and in FIG. 4B, electronic assembly 255 is shown in itsmanufactured, folded state. Electronic assembly 255 can include adesiccant and/or other drying agent, drying agent 2551. Drying agent2551 can be configured to remove any moisture that is captured withinhousing 210 during the manufacturing process, and/or any moisture thatenters the interior of housing 210 after manufacturing (e.g. whileimplanted in the patient via a small leak). In some embodiments, dryingagent 2551 comprises getter material. Implantable device 200 can beconstructed such that the “free space” within housing 210 is relativelysmall (e.g. due to efficient packaging of implantable device 200components within housing 210). The relatively small free space has anegative impact on the tolerance to moisture, and thus drying agent 2551provides a significant advantage. In some embodiments, electronicassembly 255 comprises an integrated circuit 2552 which is operativelyconnected to circuit board 2553, and drying agent 2551 (e.g. gettermaterial) is positioned on a top surface of integrated circuit 2552, asshown in FIGS. 4A-B. In some embodiments, drying agent 2551 ispositioned at multiple locations within housing 210.

Referring now to FIGS. 5A-H, various views of an electronic assembly ofimplantable device 200 are illustrated, consistent with the presentinventive concepts. Electronic assembly 255 is shown in variousunfolded, folded, and partially folded states, such as is describedhereabove in reference to FIGS. 4A-B. Electronic assembly 255 cancomprise one or more of: portion 2553 a which includes feedthrough 2556;portion 2553 c, which includes one or more capacitors 2554 c; portion2553 d, which can include antenna 240 (not shown) and opening 2557 b;and/or portion 2553 b which is operably connected to portions 2553 a,2553 c, and/or 2553 d; each as shown. Electronic assembly 255 canfurther include tabs 2553 e and 2553 f as shown, which can be used tosecure portions of electronics assembly 255 to each other.

FIGS. 5C through 5F show a series of steps of folding electronicassembly 255. In FIG. 5C, the arrow shown indicates the direction inwhich portion 2553 c is to be subsequently folded (e.g. rotated asperformed by a person or machine of a manufacturer of implantable device200). In FIG. 5D, portion 2553 c has been folded approximately 180° asshown, portion 2553 a has been rotated approximately 90° also as shown,and the arrow shown in FIG. 5D indicates the direction portion 2553 d isto be subsequently folded. In FIG. 5E, portion 2553 d has been foldedapproximately 180° as shown, and the arrow shown in FIG. 5E indicatesthe direction portion 2553 a is to be subsequently folded. In FIG. 5F,portion 2553 a has been folded approximately 90° as shown.

When electronic assembly 255 is in its folded final state, as shown inFIGS. 5F-H, capacitors 2554 c of portion 2553 c are positioned in anopen space, space 2557 a of the assembly, providing volumetricefficiency (e.g. reduced size of the final assembly). In someembodiments, opening 2557 b and portion 2553 c are sized and arranged tofrictionally engage, such as to cause electronic assembly 255 to tend toremain (e.g. during the manufacturing process) in the folded state shownin FIGS. 5F-H.

Referring now to FIGS. 6A-C, perspective, end, and side views of apartially assembled portion of implantable device 200 is illustrated,consistent with the present inventive concepts. Implantable device 200includes housing 210, which is shown partially transparent forillustrative clarity. In some embodiments, electronic assembly 255 ismanufactured with a supporting frame, such as to improve volumetricefficiency of electronic assembly 255 and housing 210 (e.g. minimize thevolume of implantable device 200). The various components of implantabledevice 200 within housing 210, such as electronic assembly 255(including its components) can be assembled as described herein, withouta separate frame (e.g. without a separate stabilizing frame). Electronicassembly 255 can be stabilized (e.g. solely stabilized) via attachmentto feedthrough 2556, which is in turn attached to housing 210, as shown.

In some embodiments, implantable device 200 comprises a length, length200L shown, that is at least two times the magnitude of the height ofdevice 200, height 200H shown. In these embodiments, implantable device200 can comprise a width, width 200 W shown, that is also at least 1.5times the magnitude of the height 200H. These minimum aspect ratios (theratios of each of length 200L and width 200 W as compared to height200H) can be chosen to prevent flipping of device 200 afterimplantation.

Referring now to FIGS. 7A-C, perspective, top, and side views of animplantable device 200 are shown, the device 200 including a connectorfor attaching to two leads 265, consistent with the present inventiveconcepts. FIG. 7D shows a magnified view of a distal portion ofconnector 280′, including fastener 284. Implantable device 200, withcertain components shown as partially transparent for illustrativeclarity, includes a pigtail or other connecting assembly, connector 280′shown, which is attached to housing 210 and surrounds feedthrough 2556.In the embodiment of FIGS. 7A-C, connector 280′ comprises a dualconnector configured to operably attach (e.g. electrically andmechanically attach) to two leads 265 (e.g. leads 265 not shown butconfigured to be attached during a clinical procedure in whichimplantable device 200 is implanted in a patient). Connector 280′ can beconfigured to electrically, mechanically, fluidly, optically, and/orsonically attach one or more components within housing 210 to one ormore components (e.g. one or more stimulating elements 260) of lead 265.Connector 280′ includes two conduits, conduits 282 a and 282 b as shown.Connector 280′ also includes two engagement assemblies 283 a and 283 b(singly or collectively connector 283), which each include a set screwand/or other securing element, fasteners 284 a and 284 b (singly orcollectively fastener 284). Each engagement assembly 283 includes anopening, ports 285 a and 285 b (singly or collectively port 285). Eachport 285 is configured to slidingly receive the proximal portion of alead 265, such as to operably connect (e.g. electrically or otherwiseoperably connect) to one or more conduits (e.g. wires, linkages, tubes,optical fibers, and/or wave guides) of lead 265 that are operablyattached to one or more stimulating elements 260 (e.g. electrode-basedstimulating elements) or other components of lead 265. Each port 285connects to one or more filaments (e.g. wires) of the associated conduit282 (filaments not shown but traveling proximally and electricallyand/or otherwise operably connecting via feedthrough 2556 to one or morecomponents internal to housing 210). Each fastener 284 is configured tobe rotated by a screwdriver or other tool, driver 286 (shown in FIG.7A), when the proximal portion of lead 265 is inserted into a port 285,such that engagement assembly 283 frictionally engages lead 265 (viafastener 284) such as to prevent detachment of lead 265 from connector280′.

In some embodiments, each engagement assembly 283 comprises a portionthat protrudes outward from the body portion of connector 280′ creatinga “bump” portion. In some embodiments, engagement assemblies 283 arepositioned such that the bump portion extends along a line parallel withthe top and bottom surfaces of implantable device 200, such that whenthe implantable device 200 is implanted in the patient, with its topsurface parallel to the patient's skin, the bump portions of engagementassemblies 283 a and 283 b do not exert a force (e.g. does not exert arubbing force) to the patient's skin (since the bump portion of eachengagement assembly 283 extends in a direction parallel to the skinsurface as opposed to orthogonal to it).

Housing 210 of implantable device 200 can include an extension portion,sealing element 205 shown. Sealing element 205 can surround feedthroughs2556, and it can be created in a molding process (e.g. a molding processin which an overmold is applied to the feedthrough portion of housing210). In some embodiments, a first portion (e.g. a first molded portion)of sealing element 205 is applied to feedthroughs 2556 (e.g. to create aseal around feedthroughs 2556 and the associated electricalconnections), and a second portion (e.g. a second molded portion) ofsealing element 205 is subsequently applied to the first portion andother locations of housing 210. Sealing element 205 can comprise epoxy.

Implantable device 200 can comprise a mechanical port, such as port 2111shown, which is configured to engage an insertion tool (e.g. insertiontool 6511 described herein). Port 2111 can comprise a recess in sealingelement 205 (e.g. the cylindrical recess shown in FIGS. 7A-B), or it cancomprise a recess positioned in another location of housing 210.

While the embodiment of FIGS. 7A-D shows an implantable device 200 witha dual connector 280′ which can be attached to two leads 265, it shouldbe appreciated that a connector 280 can be configured to attach to asingle lead 265, and the bump portion of the single engagement assembly283 can extend in a direction parallel to the patient's skin surface.

Referring now to FIGS. 8A-C, perspective, side sectional, andperspective transparent views of an anchoring element are illustrated,consistent with the present inventive concepts. As described hereabovein reference to FIG. 1, implantable device 200 can include one or moreanchoring elements, such as anchoring element 221 shown in FIGS. 8A-C.Anchor element 221 can be configured to slidingly receive, via lumen2211, an elongate portion of lead 265 (e.g. not shown, but such that theelongate portion of lead 265 passes thru lumen 2211 from one end ofanchor element 221 to the other). Anchor element 221 includes acompression assembly 2219. Compression assembly 2219 can include ahousing 2212, with lumen 2211 a therethrough. A translatable element2213 is operably attached to a set screw 2214, and element 2213 ispositioned within housing 2212 such that translatable element 2213translates in a direction perpendicular to the axis of lumen 2211 whenset screw 2214 is rotated. Translatable element 2213 includes a lumen2211 b. Lumen 2211 b can be positioned coaxial with lumen 2211 a, suchas when set screw 2214 is rotated such that lumen 2211 b is aligned withlumen 2211 a. Housing 2212 can comprise a shaped opening, configured toslidingly receive translatable element 2213, such that translatableelement 2213 can translate as described, but not rotate. Housing 2212can comprise a circular opening, configured to receive set screw 2214,such that set screw 2214 can rotate within housing 2212 and rotatablyengage translatable element 2213. Housing 2212 can comprise a recess2216, configured to engage a flange 2217 of set screw 2214. Flange 2217can engage with recess 2216 such that set screw 2214 can rotate withinhousing 2212, but not translate within housing 2212, therefore capturingset screw 2214 (e.g. such that set screw 2214 is always maintainedwithin compression assembly 2219, regardless of the number of times setscrew 2214 is rotated in either direction). Compression assembly 2219can include a compression sleeve 2215, positioned within lumens 2211a,b, as shown. Rotation of set screw 2214 in a first direction (e.g. ina clockwise direction) causes translatable element 2213 to translatetowards set screw 2214, and this translation causes compression sleeve2215 to frictionally engage an inserted lead 265 that is positionedwithin lumen 2211. Subsequent rotation of set screw 2214 in the oppositedirection, causes translatable element 2213 to translate in the oppositedirection, disengaging sleeve 2215 from lead 265.

Compression assembly 2219 can comprise a compression length (i.e. thelength of lead 265 that is compressed by assembly 2219) that is above aminimum threshold, such as to compress lead 265 along a sufficientlylong segment of lead 265 (e.g. a sufficiently long segment to avoidadversely crimping lead 265), such as a segment of at least one times,or at least two times the diameter of the lead (e.g. the diameter of thelead at the point of compression). In some embodiments, the compressionlength of compression assembly 2219 comprises a length of at least 0.051mm, at least 0.102 mm, or at least 0.200 mm. In some embodiments,compression assembly 2219 compresses lead 265 along two or more discretesegments.

Compression assembly 2219 can be configured to radially compress lead265 at least 10% of the diameter of the lead (e.g. a lead with anuncompressed diameter of 1.3 mm would be compressed at least 0.13 mm),and/or no more than 33% of the diameter of the lead (e.g. a lead with acompressed diameter of 1.3 mm would be compressed no more than 0.43 mm).

Anchor element 221 can include one or more fixation points,circumferential recess 2218 (e.g. such as recesses 2218 a and 2218 bshown). Surgical clips or sutures can be placed around a recess 2218 andinto tissue, such as to fixate anchor element 221 and an inserted lead265 to tissue.

Referring now to FIG. 9, a top view of an electronic assembly ofimplantable device 200 is illustrated, consistent with the presentinventive concepts. Electronic assembly 255 is shown in an unfoldedstate. Electronic assembly 255 comprises various portions, such asregions B, C, D, and E shown. Electronic assembly 255 can comprise oneor more portions of insulating tape (e.g. a polyimide tape) and/or otherinsulating material portions, insulator 2558 shown. In some embodiments,an insulator 2558 is positioned over one or more regions of electronicassembly 255 such that when assembly 255 is folded in manufacturing(e.g. as described hereabove in reference to FIGS. 5A-H), opposingelectrically conductive portions of assembly 255 do not contact eachother. For example, an insulator 2558 can be positioned such that a DCblocking capacitor 2554 and a DC node do not electrically shorttogether. Insulator 2558 can comprise a portion that is positioned alongthe sides of components C1 and L1 shown (e.g. along line A). Insulator2558 can comprise an upper boundary that is no lower than the topsurface of component L1 and no higher than the top surface of componentC1. In some embodiments, adhesive is applied between components atregion B and region C. In some embodiments, insulator 2558 can comprisea portion that is positioned over components C18-C23 shown (e.g.components positioned in region E). In some embodiments, a serial numberlabel is positioned in region D.

Referring now to FIG. 10, an exploded view of an external device isillustrated, consistent with the present inventive concepts. Externaldevice 500 includes housing 510, comprising top housing 510 a and bottomhousing 510 b. Housing 510 can comprise one or more metal and/or plasticmaterials, such as polycarbonate and/or acrylonitrile butadiene styrene(ABS). Positioned between housings 510 a-b are various componentsconfigured to transmit power and/or data to an implantable device 200,and perform other functions, as described herein. External device 500includes electronic assembly 555, which is shown positioned on top of acopper shield, shield 556 shown. Copper shield 556 is positioned on topof a ferrite disk, disk 557, which in turn is positioned on top ofantenna assembly 540. One or more screws, screws 513 (three shown),attach components 555, 556, 557, and 540 to bottom housing 510 b viamating bosses 514 (three shown) into which screws 513 rotatably engage(e.g. engage threads of boss 514). In some embodiments, screws 513 arerotatably engaged with a minimum torque (e.g. to minimize gaps betweenthe layers), such as a torque of at least 10 in-oz, such as at least 14in-oz, or at least 16 in-oz. In some embodiments, copper shield 556 isadhered to ferrite disk 557. In some embodiments, antenna 540 is adheredto ferrite disk 557. In some embodiments, both copper shield 556 andantenna 540 are adhered to ferrite disk 557 (e.g. in the orientationshown in FIG. 10), such as to create a laminate construction whichmaximizes the effectiveness of the shielding provided, and/or eliminatesor at least minimizes gaps between layers that could result in detuning.

External device 500 includes a battery, capacitor, or other energystorage element, power supply 570 shown. Power supply 570 can beattached to electronic assembly 555 via connector 572 shown. Connector572 can comprise a double-sided adhesive pad. Power supply 570 can bereplaceable and/or rechargeable. In some embodiments, power supply 570comprises a lithium ion battery. External device 500 can comprise one ormore contacts positioned on the external surface of housing 510, such ascontacts 571 (three shown). Contacts 571 can comprise pogo pins or othercontacts that are electrically connected to charging circuitry ofelectronic assembly 555, such as to allow charging of power supply 570.For example, contacts 571 can be constructed and arranged to receivepower from mating contacts of charger 61 as described herebelow inreference to FIGS. 17A-C.

External device 500 can comprise one or more user interface components,such as indicator 581 shown. Indicator 581 can comprise an indicatorlight and/or a display. In some embodiments, indicator 581 comprises alight pipe which is positioned above a light-emitting device such asabove an LED of electronic assembly 555. In some embodiments, indicator581 comprises a speaker or other audio output component (e.g. a buzzer).Indicator 581 can provide various information to the patient or otheruser, such as: status of connection with implantable device 200; batterystatus (e.g. battery level, low battery, and the like); programinformation (e.g. program number); therapy information (e.g. amplitudeor other therapy level); programmer 600 connection status; andcombinations of one or more of these.

Referring now to FIG. 11 A-D, a perspective top view, a side view, aside sectional view, and another side sectional view and of an interfaceassembly for operably attaching a trialing interface 90 to two leadassemblies 265 is illustrated, consistent with the present inventiveconcepts. Interface connector 95 comprises housing 9510 including base9511 and first hinged portion 9512 a and second hinged portion 9512 b(singly or collectively hinged portion 9512). Hinged portions 9512 a and9512 b are rotatably attached to a mid-portion of base 9511, and eachcan rotate in the directions shown in FIG. 11B. In FIG. 11B, hingedportion 9512 a is shown in an “open” position (e.g. a position in whicha lead 265 can be inserted or removed), and hinged portion 9512 b isshown in a “closed position” (e.g. position in which the proximal end ofa lead 265 is secured in place and electrically and/or otherwiseoperably connected to trialing interface 90).

In some embodiments, interface connector 95 is constructed and arrangedsuch that hinged portion 9512 a-b interfere with each other duringrotation, such as to limit the amount of rotation each can undertake.For example, rotation of hinged portion 9512 a is limited to the pointat which hinged portion 9512 a contacts hinged portion 9512 b, e.g.location L1 shown in FIG. 11B. In some embodiments, only one of hingedportions 9512 can be opened (e.g. fully opened) at a time (e.g. due to amechanical stop provided by contact between the hinged portion 9512 aand 9512 b when one is in an open position).

Hinged portions 9512 a and 9512 b can include one or more projections,such as tabs 9513 a and 9513 b, respectively, as shown. Similarly, base9511 can comprise one or more projections, such as the two tabs 9514 ashown relatively opposite projection 9513 a (e.g. and similar tabs 9514b not shown but relatively opposite projection 9513 b). Interfaceconnector 95 can be constructed and arranged such that a user (e.g. aclinician that implants one or more implantable devices 200) can rotatea hinged portion 9512 by engaging a hinged portion 9512 (e.g. grasping aprojection 9513) and engaging base 9511 (e.g. gasping at a projection9514) and applying a force to cause a rotation (e.g. a pivoting force totransition hinged portion 9512 from an open to closed condition, or viceversa). In some embodiments, interface connector 95 is constructed andarranged such that a user can use a single hand to transition a hingedportion 9512 from an open condition to a closed condition, or vice versa(e.g. fingers of a single hand apply opposing forces to base 9511 and ahinged portion 9512).

Each hinged portion 9512 includes a lumen 9515 through which a lead 265can be inserted when the associated hinged portion is in an openposition. Subsequent closure of the hinged portion 9512 causes lead 265to be secured within interface connector 95 and to operably connect withvarious components of lead 265. For example, conductive portions of lead265, contacts 267 (e.g. contacts which are each electrically connectedto a stimulation element 260), can electrically connect to one or morepogo pins or other electrical contacts of connector 95, contacts 9516.

Securing of a lead 265 via inserting of lead 265 into a lumen 9515 androtation of the associated hinged portion 9512 to a closed position,electrically and/or otherwise operably connects lead 265 to interfaceconnector 95. Interface connector 95 includes connector 9520 which isoperably attached to at least contacts 9516 via cable 9521. Connector9520 can be operably connected to a trialing interface, such as trialinginterface 90 described herebelow in reference to FIGS. 12A-B.

Referring now to FIG. 12A-B, a perspective view and a schematic view ofa stimulation apparatus comprising a trialing interface and a leadconnector are illustrated, consistent with the present inventiveconcepts. Trialing interface 90 comprises a housing, housing 9010, whichsurrounds an electronic assembly, assembly 9030. Electronic assembly9030 is electrically attached to a connector, connector 9020, such as aconnector with at least 10 contacts, such as approximately 18 contacts.Electronic assembly 9030 can be electrically attached to connector 9020via cable 9021 (as shown in FIG. 12A). Trialing interface 90 furthercomprises interface connector 95, which includes connector 9520.Connector 9520 is configured to electrically attach to connector 9020(e.g. connector 9520 comprises mating contacts, such as at least 10contacts, such as approximately 18 contacts).

Interface connector 95 includes housing 9510. Interface connector 95 isconfigured to operably (e.g. at least electrically) attach to one ormore leads 265 (e.g. removably attaching to leads 265 a and 265 b shownin FIGS. 12A-B). Each lead 265 can include one or more stimulationelements 260 a and 260 b, respectively (e.g. two, four, six, eight, ormore stimulation elements 260). Each lead 265 connects to interfaceconnector 265 via connector 9540 as shown. In some embodiments, housing9510 comprises two hinged portions, which can be positioned (e.g. via asingle hand of an operator) about one or more leads 265 (e.g. asdescribed hereabove in reference to FIGS. 11A-D). In some embodiments,interface connector 95 is configured to operably attach to a single lead265. In some embodiments, interface connector 95 is configured tooperably attach to three or more leads 265, such as four leads 265.Interface connector 95 can include cable 9521, as shown in FIG. 12A,which electrically attaches connector 9520 to connector 9540.

Electronic assembly 9030 is configured to provide stimulation energy toone or more stimulation elements 260 of one or more leads 265 (e.g. viaconnectors 9020, 9520, and 9540). As described hereabove in reference toFIG. 1, interface connector 95 can comprise a single-use disposablecomponent, used in a single clinical procedure on a single patient,while the remaining portions of trialing interface 90 (e.g. housing 9010and its surrounded components) are for use in multiple clinicalprocedures (e.g. on the same or multiple patients).

In some embodiments, electronic assembly 9030 includes detectioncircuitry 9031, and interface connector 95 comprises detection circuitry9531. Detection circuitry 9031 is electrically connected to one or morecontacts of connector 9020, and detection circuitry 9531 is connected toone or more mating contacts of connector 9520. Via circuitry 9031 and9531, trialing interface 90 is configured to detect proper connection ofconnector 9520 to connector 9020 (e.g. perform one time and/or repeatedchecks that a proper electrical and/or other connection exists betweenconnectors 9520 and 9020). In some embodiments, detection circuitry 9531comprises a connection (e.g. an electric short or other known resistanceconnection) between two or more contacts of connector 9520, andelectronic assembly 9030, via detection circuitry 9031 can detect aproper connection between connectors 9020 and 9520 has been made basedon this connection of known resistance. In some embodiments, theconnection is determined using an alternating current (AC) signal.Avoidance of a direct current (DC) signal is advantageous as it avoidsuncomfortable and/or unsafe stimulation of the patient (e.g. due to abend and/or break in lead 265, or other event that causes shorting ofwires of lead 265). In some embodiments, the AC signal provided byelectronic assembly 9030 comprises a digital pulse (e.g. with a pulsewidth of approximately 2 μsec and at a voltage level less than 10V, suchas less than 5V, or approximately 3V). Electronic assembly 9030 isconfigured to detect a “high” state during the pulse, and then a “low”state after the pulse. This check for a proper connection can berepeated (e.g. at approximately a 10 Hz rate), and trialing interface 90can detect if a connect or disconnect of connectors 9020 and 9520 occurs(e.g. a connect or disconnect of interface connector 95 from theremaining portion of trialing interface 90).

In some embodiments, trialing interface 90 is configured to detectproper connection of one or more leads 265. For example, trialinginterface 90 can be configured to perform an impedance measurement thatprovides information about the state of connectivity of lead 265 withboth trialing interface 90 and tissue. A high (e.g. open) impedance isindicative of an improper connection.

In some embodiments, if trialing interface 90 detects connectors 9020and 9520 being connected (i.e. detects connectors 9020 and 9520transitioning from a disconnected state to a connected state), andelectronic assembly 9030 is currently (e.g. at the time of theconnection) attempting to deliver a stimulation waveform (i.e. deliverstimulation energy) to the patient (e.g. via one or more stimulationelements 260), electronic assembly 9030 can be configured to stop signaldelivery to the patient (e.g. avoid full amplitude signal delivery tothe patient), and initiate a new stimulation delivery in which amplitudelevel is slowly ramped up (e.g. to avoid the patient getting fullstimulation energy at the time of connection). For example, theamplitude can be ramped up over a period of 1s to 10s to avoid fullamplitude delivery at the time of a connection that may be perceived asunpleasant by the patient. In some embodiments, trialing interface 90 isconfigured to prevent delivery of full amplitude stimulation energy(and/or any significant amplitude of stimulation energy) unless a properconnection between connectors 9020 and 9520 is detected.

Referring now to FIG. 13A-C, perspective views of a single connector215′ attached to a connector 220 and a dual connector 215″ attached to aconnector 220, respectively, are illustrated, consistent with thepresent inventive concepts. As shown in FIG. 13A, the array of pins 206of connector 220 are slidingly received by the array of receptacles 216of connector 215′. Connector 215′ includes single conduit 262 of lead265 or a single conduit 282 of lead connection assembly 280. As shown inFIG. 13B, the array of pins 206 of connector 220 are slidingly receivedby the array of receptacles 216 of connector 215″. Connector 215″includes dual conduits 262 a, 262 b of two leads 265 or conduits 282 a,282 b of two lead connection assemblies 280 or a dual lead connectionassembly 280′. In some embodiments, as shown in both FIGS. 13A and 13B,a sealing element 205 is applied to surround at least a portion ofhousing 210, connector 220, and/or connector 215, such that sealingelement 205 prevents contamination from entering locations withinhousing 210 and/or adversely affecting the connection made betweenconnector 215 and an attached component.

Referring additionally to FIG. 13C, apparatus 10 can include one or morestylets 1700, such as stylets 1700 a and 1700 b shown, and implantabledevice 200 can comprise one or more stylet entry ports, such as ports207 a and 207 b shown. Each entry port 207 can be connected to a lumenof a lead 265 and/or lead connection assembly 280, such as lumens 208 aand 208 b. Each stylet 1700 can include an elongate filament 1701 whichcan be connected to a handle 1702, (e.g. filaments 1701 a and 1701 bconnected to handles 1702 a and 1702 b, respectively). Each filament1701 can be inserted into a lumen 208 such as to provide rigidity in theadvancement of the lead 265 (or lead connection assembly 280) throughtissue. Filament 1701 can comprise a filament that is flexible and/ormalleable, such as a malleable filament whose shape can be curved orotherwise modified as desired to assist in the insertion of a lead 265through tissue (e.g. a lead comprising one or more stimulation elements260 as shown). In some embodiments, a single stylet 1700 is used tosequentially advance a first lead 265 a and then a second lead 265 b.Each entry port 207 includes an opening with a trajectory that allowsstylet 1700 to be positioned eccentric to the associated lumen 208. Inother words, the proximal portion of each lumen 208 (the portionproximate opening 207 is curved as shown. This configuration of lumen208 and opening 207 avoids any additional volume needed to be added tohousing 210, while allowing stylet 1700 to remain centered in theassociated lead 265 such that insertion of lead 265 is performed with asimilar technique to that used when inserting a lead not attached to astimulator housing.

In some embodiments, sealing element 205 (or another portion of housing210) comprises a receptacle for engaging an implantation tool (e.g.insertion tool 6511 described herein), such as port 2111 describedhereabove in reference to FIGS. 7A-B.

Referring now to FIGS. 14A-B, perspective views of an implantable device200 are illustrated, consistent with the present inventive concepts.Implantable device includes housing 210, and connector 220 as describedherein. Connector 220 comprises an array of pins 206 that are slidinglyreceived by an array of receptacles 216 of connector 215″. Connector215″ includes dual conduits 262 a, 262 b of two leads 265 or conduits282 a, 282 b of two lead connection assemblies 280 or a dual leadconnection assembly 280′. In some embodiments, a sealing element 205 isapplied to surround at least a portion of housing 210, connector 220,and/or connector 215, such that sealing element 205 preventscontamination from entering locations within housing 210 and/oradversely affecting the connection made between connector 215 and anattached component.

Implantable device 200 can comprise one or more stylet entry ports, suchas ports 207 a and 207 b shown. Each entry port 207 can be connected toa lumen of a lead 265 and/or lead connection assembly 280, such aslumens 208 a and 208 b, such as to cooperate with a stylet 1700 asdescribed hereabove in reference to FIG. 13C.

A set of wires 217 are electrically connected to the array of pins 206.For illustrative clarity, only 4 wires 217 are shown in FIGS. 14A-B,however each pin 206 is electrically connected to a separate wire 217(e.g. 32 pins 206 are connected to 32 separate wires 217). The arraywires 217 travel into dual conduits 262 a, 262 b of two leads 265 orconduits 282 a, 282 b of two lead connection assemblies 280 or a duallead connection assembly 280′. Wires 217, at their point of connectionto pins 206, can be arranged in 2 linear arrays of wires positioned in 2planes (e.g. when pins 206 are arranged in two rows as shown). Each wire217 can travel, in a path comprising a curvilinear trajectory, and in arelatively parallel arrangement to one or more wires 217 in proximity toit, and enter into a conduit 262 a, 262 b of a two lead 265 or a conduit282 a, 282 b of a connection assembly 280 or a dual lead connectionassembly 280′. The collective pathways of wires 217 can be arranged toavoid the lumen of ports 207.

Referring now to FIGS. 15A-L, a series of views of an implantationprocedure for implantable device 200 is illustrated, consistent with thepresent inventive concepts. Implantable device 200 can be configured asa “ported-version”, in which leads 265 are attachable by the clinician,and/or an “integrated-version” (a pre-attached-version), in which leads265 are attached during the manufacturing of implantable device 200. Asdescribed herebelow, each implantable device 200 can be implanted in thepatient using a single incision (i.e. avoiding multiple incisions).Implantable device 200 can be implanted using both a tunneling tool,tool 6504, for creating a tunnel in tissue, a lead pushing tool, tool6505, configured to push lead 265 through that tunnel, and/or othertools as described herebelow. Tunneling tool 6504 can comprise ahandheld device (e.g. with an effective length of approximately 10 cm)that is used to create a subcutaneous pathway and pocket for theplacement of implantable device 200. The implantation steps below aredescribed in reference to positioning implantable device 200 proximatethe patient's spine.

The patient can be positioned, prepped, and draped per clinicalprotocols. A local anesthetic can be injected at the needle insertionsite. A needle assembly 6506 including a needle 6506 a and a stylet 6506b can be inserted into the epidural space, such as with a bevel of theneedle facing up at an angle of 45° or less. The stylet 6506 b is thenremoved from the needle 6506 a. Proper positioning of the needle tip inthe epidural space can be performed using the “loss-of-resistance”technique.

Lead 265 can include a pre-loaded bent stylet, stylet 6507. This stylet6507 can extend to the tip of the lead. The lead 265 including itsstylet 6507 can be inserted through the insertion needle 6505 a. In someembodiments, lead 265 includes multiple stylets 6507 (e.g. multipledifferent stylets 6507 a, 6507 b, and so on). If exchange of a stylet6507 is desired, the existing stylet (e.g. a stylet 6507 a) can becarefully pulled out of the lead 265, and a different stylet (e.g. astylet 6507 b) inserted. If resistance is encountered during a stylet6507 insertion, rotation of the lead 265 and/or stylet 6507 can beperformed (e.g. a rotation that occurs after a small withdrawal of thestylet 6507).

Lead 265 including a stylet 6507 can be advanced to the appropriatevertebral level under fluoroscopic guidance. A sufficient length of lead265 (e.g. at least 10 cm, or approximately three vertebrae) shouldreside in the epidural space (e.g. to aid in stabilization of lead 265).

If multiple leads 265 are to be implanted, the above steps can berepeated for each lead 265.

Referring to FIG. 15A, while holding lead 265 in place, the interfaceconnector 95 is connected to the proximal end of each lead 265 byopening a hinged lid of connector 95 and inserting the proximal end ofeach lead 265 into the access port on the side of the lid. Averification that lead 265 is fully inserted into connector 95 can beperformed, such as through a visual observation port on the top of thehinged lid(s). The lid(s) is then closed, which can be confirmed by thepresence of a snapping sound provided by connector 95. If a single lead265 is inserted, it can be inserted into a predetermined port ofconnector 95 (e.g. the bottom access port A shown in FIG. 15a ).

In some embodiments, the female end of interface connector 95 (e.g. alarger end) can be connected to an extension cable of apparatus 10. Thisextension cable can be connected to a trial stimulator device ofapparatus 10, such as trialing interface 80 and/or 90 described herein.

In some embodiments, the connections can be tested (e.g. impedancetested), such as by using clinician programmer 600″ described herein.Inadequate connections can be reconnected and retested until asatisfactory result is achieved.

If paresthesia coverage is desired, an appropriate set of stimulationparameters can be identified, such as parameters beginning at arelatively medium pulse width and frequency range. The stimulation canbe delivered, and an increase in amplitude performed while asking thepatient questions (e.g. close-ended questions) to identify thatpatient's perception threshold, a discomfort threshold, and/or an areaof coverage (e.g. paresthesia coverage).

In some embodiments, a fluoroscopic, ultrasonic, and/or other image ofplacement of lead 265 is taken, such as for record-keeping purposes.

If performing a “staged trial”, using a lead 265 to be permanentlyimplanted, interface connector 95 can be detached from lead 265, andanchoring of lead 265 can be performed (e.g. as described herebelow inreference to FIG. 15B). If performing a “temporary trial” using a shortterm temporary implanted lead (e.g. a temporarily implanted lead 265),the excess portion of lead 265 can be coiled and the lead 265 andinterface connector 95 can be covered (e.g. with gauze and dressing).

Referring now to FIG. 15B, anchoring of lead 265 can be performed byfirst removing the lead 265 stylet 6506, such as using fluoroscopy orother imaging to ensure that the lead 265 position does not change. Asshown in FIG. 15B, a small midline incision can be made at the lead 265skin entry site. An anchor element 221 can be placed over lead 265 anddown to the supraspinous ligament or down to the deep fascial tissue. Aconfirmation that the tip of the anchor element 221 has been pushed intothe ligamentous tissue can be performed.

A suture can be placed in the supraspinous ligament or deep facia, thenlead 265 can be inserted through the suture and the suture tied off(e.g. to an eyelet of anchor element 221). After suturing to the eyelet,a set screw of anchor element 221 can be tightened (e.g. using a torquewrench, such as torque wrench 6508 described herein). A clicking soundcan be provided when anchor 211 is locked. After the set screw istightened, a second eyelet of anchor element 221 can be sutured to thesupraspinous ligament or deep fascia. The secure attachment of lead 265,via anchor element 221, can be checked. A check can be performed toensure that lead 265 has not moved, such as by performing a teststimulation and/or using imaging (e.g. fluoroscopic imaging) asnecessary. If it is determined that lead 265 has undesirably migrated,the set screw can be loosened, lead 265 repositioned, and the set screwretightened. This process described in reference to FIG. 15B can berepeated for placement of additional leads 265.

Implantation of a ported-version of implantable device 200 is describedherebelow in reference to FIGS. 15C-G.

If a staged trial was performed, as described hereabove, the followingsteps 1-5 are performed. If it wasn't a staged trial, only steps the 3-5are performed.

(1) The lead extension is cut (e.g. with scissors or other cutting toolof apparatus 10), proximal to its connector. The remaining portion ofthe lead extension is pulled out through the exit wound site anddiscarded.

(2) Using torque wrench 6508, a set screw of a connector boot of thelead extension is loosened (e.g. rotated until a click is heard). Theconnector boot is removed and discarded.

Steps (1) and (2) can be repeated for additional leads 265 that havebeen inserted into the patient.

(3) The proximal end of the lead 265 can be cleaned, and then insertedinto the implantable device 200 connector (e.g. until it is fullyinserted and a set screw ring is located directly under the set screw).

(4) A check that the lead 265 is fully inserted is performed.

(5) Using torque wrench 6508, the set screw of implantable device 200 istightened (e.g. until a click is heard, indicating the lead 265 isproperly secured).

Steps (3) through (5) can be repeated for any additional leads 265 thathave been inserted into the patient.

Referring now to FIG. 15C, an external device 500 can be included in asterile bag, sterile bag 6509, as shown. The external device 500 can bepositioned proximate the implantable device 200 that has been implantedin the patient, such as to perform a test stimulation. A check of adesired physiologic response can be performed during the teststimulation. External device 500 can be oriented such that any buttonsor other controls of user interface 580 of external device 500 arefacing away from the implantable device 200 when performing the teststimulation.

Referring now to FIG. 15D, the desired implantation site for theimplantable device 200 can be located lateral to the midline incision.This final implantation site can be pre-determined via consultation withthe patient prior to the implantation procedure. With the externaldevice 500 still in the sterile bag 6509, the periphery of the externaldevice 500 can be traced with a surgical marker of apparatus 10, sterilemarking tool 6510 shown, such as while the external device 500 iscentered over the desired implantation site of implantable device 200.

Referring now to FIG. 15E, the lower distal end of a tunneling tool ofapparatus 10, such as tunneling tool 6504 described herein, is insertedinto the midline incision, with the top portion of tunneling tool 6504positioned above the skin (e.g. to function as a depth guide and/or togauge length). Using blunt dissection, a subcutaneous tissue path fromthe midline incision site to the final implant location of implantabledevice 200 is performed by advancing the tip of tunneling tool 6504until the tip of tunneling tool 6504 is approximately the length ofimplantable device 200 from the center of the traced outline of externaldevice 500 described hereabove. Tunneling tool 6504 can include markings6504 a (e.g. markings equidistantly spaced, such as at a separationdistance of 1 cm) that are used to measure the distance from theincision site to the final implant location of implantable device 200.Tunneling tool 6504 can be maintained relatively shallow during tissuetunneling, without puncturing the skin. The pocket can be irrigated,such as with sterile saline solution and/or antibiotic solution.Tunneling tool 6504 is configured to cause implantable device 200 to bepositioned below the skin at a constant depth and approximately parallelto the skin, such as to ensure successful transmissions of power and/ordata between implantable device 200 and an external device 500 duringuse.

Referring now to FIG. 15F, tunneling tool 6504 can be used as atemplate. Tunneling tool 6504 can be placed on the skin and thetunneling path traced using the top portion of the tool 6504 from themidline incision to the center of the outline of the external device 500location.

The tip of a tool configured to insert implantable device 200, insertiontool 6511 (shown in FIG. 15G), is inserted into a receptacle ofimplantable device 200 (e.g. port 2111 described hereabove in referenceto FIG. 7A-B), such as a receptacle proximate the location where lead265 or a lead extension protrudes from housing 210 of implantable device200. Insertion tool 6511 can be sized and configured to frictionallyengage implantable device 200 during the positioning process.

Referring now to FIG. 15G, the tunneling tool 6504 (not shown in FIG.15G) can be withdrawn until only its tip portion remains within thetissue tunnel (e.g. in order to retain the tunnel location and path).The insertion tool 6511, with attached implantable device 200 is madeavailable (e.g. positioned proximate the tunnel location) as shown. Thetunneling tool 6504 is then completely removed, and soon thereafter theimplantable device 200 is advanced into the tissue tunnel (e.g. in aparticular orientation, such as with a logo or other marker facingtoward the patient's skin). Forceps can be used to lift the superioredge of the midline incision to further facilitate insertion.

The implantable device 200 is advanced with a pushing motion along thesubcutaneous tissue path until the device 200 is located at the centerof the external device 500 marked outline. Verification of properplacement can be performed, such as using palpation.

If excessive resistance is encountered upon initial insertion of theimplantable device 200 into the tissue tunnel created by tunneling tool6504, a check that the implantable device 200 is positioned (e.g.oriented) properly within the tissue tunnel can be performed. Ifinsertion tool 6511 is detached from the implantable device 200, agentle pull back on the lead(s) 265 can be performed to remove theimplantable device 200 from the tissue tunnel.

If excessive resistance inserting the implantable device 200 isencountered after multiple attempts, alternative tools, such as forceps,can be used for placement.

Once properly positioned, while slight pressure is applied to theimplantable device 200, insertion tool 6511 is detached (e.g. bysimultaneously applying a pulling force), leaving the implantable device200 in place.

A check of connections can be performed, such as using an impedancemeasurement (e.g. as described herein). If impedance is at an undesiredlevel, connections can be checked and/or remade, and an impedance checkrepeated.

Any excess length of lead 265 can be looped and/or tucked into theincision site and/or tissue tunnel.

The midline incision is closed, and the wound dressed.

While the method described in reference to FIGS. 15C-G provides onemethod of implanting a ported-version of an implantable device 200,alternative methods can be performed. For example, one alternativemethod is described immediately herebelow.

Leads 265 are placed and anchored, for example as described hereabove.

The final pocket site for the implantable device 200 is located asdesired (e.g. a location pre-determined with the patient prior to theimplantation surgery). With an external device 500 in a sterile bag6509, the outline of the external device 500 is traced with sterilemarking tool 6510 with the external device 500 centered over the desiredimplantable device 200 final pocket site.

A small incision is made near the desired pocket site.

The desired route of the tissue tunnel is marked on the patient's skin.

A local anesthetic is administered along the intended tissue tunnelpath.

If necessary or at least desired, a tissue tunneling device, tunnelingtool 6512, is bent to conform to the patient's body. Tunneling tool 6512can comprise a handle, a malleable (e.g. stainless steel) rod with asharp tip that is used to create a tissue tunnel (i.e. a subcutaneouspathway) for the passage of lead 265 and/or a lead extension. Tunnelingtool 6512 can further include a sleeve (e.g. a plastic sleeve).

Tunneling tool 6512 can be used to create a subcutaneous tunnel betweenthe lead(s) 265 incision site and the implantable device 200 pocketincision site until the tool 6512 is visible and accessible at the exitpoint (e.g. the exit of the tunnel at the surface of the skin).

Once in place in the created tissue tunnel, a handle (e.g. a loop) oftunneling tool 6512 can be grasped with one hand, while holding itssleeve with the other hand. The shaft of the tool 6512 can be pulled outthrough the sleeve, leaving the sleeve in place.

A lead 265 (or lead extension) can be pushed through the tool 6512sleeve, and then the sleeve withdrawn from the tissue tunnel.

The proximal end(s) of the lead 265 can be pulled out of the exit point.

The proximal end(s) of the lead 265 can be cleaned, and then insertedinto the implantable device 200 connector (e.g. until it is fullyinserted and a set screw ring is located directly under the set screw),such as is described hereabove in reference to FIG. 15B hereabove.Further implantation steps can be performed as described in reference toFIGS. 15B-G.

Implantation of an integrated-version of implantable device 200 isdescribed herebelow in reference to FIGS. 15H-K.

Referring now to FIG. 15H, the patient is positioned, prepared, anddraped. A local anesthetic is injected at the needle insertion site.Under fluoroscopic guidance, the distal portion of a tearawayintroducer, introducer 6513, has been inserted into the patient (e.g.into the epidural space of the patient). In the embodiment of FIG. 15H,two introducers 6513 have been inserted (e.g. to implant two leads 265).

Introducer 6513 can include needle 6513 a, stylet 6513 b, and sheath6513 c. During insertion, the angle of the insertion needle 6513 a ofintroducer 6513 can be maintained at an angle of 45° or less. Steepangles increase the insertion force of stylet 6513 b, and can alsopresent more of an opportunity for stylet 6513 b to pierce lead 265 andcause tissue damage. The distance between the sheath 6513 c opening andthe needle 6513 a opening, can be below a maximum, such as is describedherebelow in reference to FIG. 16. This distance can be considered bythe clinician when entering the epidural space.

Stylet 6513 b is then removed from sheath 6513 c. Entry into theepidural space can be verified (e.g. using the loss-of resistancetechnique).

Needle 6513 a is then removed from sheath 6513 c.

Lead 265 is loaded (e.g. pre-loaded) with stylet 6507, such that stylet6507 extends to the tip of lead 265. In some embodiments, multiple leads265 are each loaded with a stylet 6507, such as the two leads 265 andtwo stylets 6507 shown in FIG. 15I. Subsequently, each lead 265 andloaded stylet 6507 is slowly inserted through a sheath 6513 c.

In some embodiments, an exchange of stylet 6507 can be performed (e.g.with a stylet 6507 of a different configuration to the stylet loadedinto lead 265), such as a stylet 6507 exchange as described hereabove.

In some embodiments, to facilitate loading of a stylet 6507 into anintegrated lead 265, the lead 265 is first aligned with the generaldirection of the stylet lumen path of the implantable device 200, asshown in FIG. 15J. Once aligned, the tip of the stylet 6507 can beinserted into the associated opening of implantable device 200 andstylet 6507 advanced into lead 265.

Subsequently, lead 265 can be advanced to the appropriate vertebrallevel, such as an advancement performed under visual guidance (e.g.fluoroscopy and/or ultrasound imaging), as shown in FIG. 15K. Sufficientlength of lead 265 (e.g. at least 10 cm and/or approximately threevertebrae) should reside in the epidural space (e.g. to aid instabilization of lead 265).

If implantable device 200 comprises dual leads 265, the second lead 265can be implanted in a similar fashion.

While holding the one or more leads 265 in place, impedance levels canbe checked and/or test stimulation can be performed (e.g. using anexternal device 500 positioned in sterile bag 6509). If paresthesiacoverage is desired, an appropriate set of stimulation parameters can beidentified, such as parameters beginning at a relatively medium pulsewidth and frequency range. The stimulation can be delivered, and anincrease in amplitude performed while asking the patient questions (e.g.close-ended questions) to identify that patient's perception threshold,a discomfort threshold, and/or an area of coverage (e.g. paresthesiacoverage).

The tearaway introducer sheath 6513 c can be removed (e.g. each half ata time) by grasping hub tabs of the sheath 6513 c as shown in FIG. 15L.

Anchoring of lead 265 can be performed, such as using anchor element 221as described hereabove in reference to FIG. 15B.

Proximal to the one or more anchor elements 221, a small loop in thelead 265 can be created (e.g. to create slack).

Implantable device 200 can be implanted in the final pocket site, asdescribed hereabove.

In some embodiments, a lead extension is positioned between implantabledevice 200 and lead 265 (e.g. between housing 210 and lead 265). Inthese embodiments, a desired location of a tissue tunnel is marked (e.g.on the patient's skin). Anesthetic is administered along the intendedtissue tunnel path.

If necessary or at least desired, a tissue tunneling device, tunnelingtool 6512 described hereabove, is bent to conform to the patient's body.

A small incision is created at the desired exit site, and the tunnelingtool 6512 is prepared for use (e.g. a protective cap is removed ifpresent).

A tissue tunnel is created in the subcutaneous tissue between themidline incision and the exit site until the shaft of the tunneling tool6512 is visible and accessible at the exit point. In order to minimizethe risk of infection, tunneling can be performed away from the initialincision site, in the contralateral and superior direction.

Once in place in the created tissue tunnel, a handle (e.g. a loop) oftunneling tool 6512 can be grasped with one hand, while holding itssleeve with the other hand. The shaft of the tool 6512 can be pulled outthrough the sleeve, leaving the sleeve in place.

The proximal end of the lead 265 can be cleaned, and then inserted intoa connector of the lead extension (e.g. until it is fully inserted and aset screw ring is located directly under the set screw). If anobstruction is suspected when inserting lead 265 into the leadextension, the set screw can be loosened (e.g. using torque wrench 6508)and/or the lead 265 can be gently rotated.

Once proper insertion of the lead 265 is confirmed, the set screw can betightened (e.g. using torque wrench 6508), such as a tightening thatproceeds until a clicking sound is observed.

An appropriately-sized pocket in the tissue is formed (e.g. using bluntdissection), on either side of the midline for coiled excess lead 265and/or lead extension.

A small loop is created in lead 265 for slack.

The free end of the lead extension is passed through the sleeve oftunneling tool 6512 until it emerges from the exit site. Excess slack isremoved by pulling the lead extension from the exit site.

These steps can be repeated for a second lead extension.

Interface connector 95 can be attached to the lead extension, such as isdescribed hereabove in reference to FIGS. 11A-D, and a test stimulationperformed to verify desired response of the implantable device 200.

If a staged trial using a permanent lead 265 is being performed, a smallsuture can be used to close the exit site of the lead extension. Tapecan be placed and a stress relief loop created in the lead extension,and the wound dressed.

The midline incision can be closed and covered with gauze and dressing.The lead extension can be coiled and covered with gauze and dressing atthe exit site.

In some embodiments, implantable device 200 is implanted to performperipheral nerve stimulation. For example, implantable device 200 can beimplanted to stimulate one or more peripheral nerves selected from thegroup consisting of: suprascapular nerve; brachial plexus nerve;intercostal nerve; ulnar nerve; median nerve; radial nerve; clunealnerve; femoral nerve; ilioinguinal nerve; sacral nerve; scrotal nerve;pudendal nerve; sciatic nerve; peroneal nerve; sural nerve; tibialnerve; and combinations of these.

In an implantation procedure in which peripheral nerve stimulation is tobe accomplished, the patient can be positioned, prepped, and draped perclinical protocols. The area of the patient's peripheral nerve(s) to bestimulated can be mapped and the planned trajectory marked on the skin.

A local anesthetic can be injected at the needle insertion site.

If necessary or desired, a puncture incision can be made beforeinserting a needle or introducer.

A needle and/or introducer can be advanced through the incision in thedirection of the peripheral nerve. If using a needle, an included styletcan be removed, leaving the needle in place. If using an introducer, anincluded needle can be removed leaving a sheath in place.

One or more leads 265 are provided, such as including bent stylet 6507.The stylet 6507 should be positioned to extend to the tip of the lead265. The lead 265, including stylet 6507, is slowly inserted, throughthe insertion needle or sheath.

If an exchange of stylet 6507 is desired, the existing stylet 6507 canbe pulled out, and a different stylet 6507 inserted, as describedhereabove.

These steps can be repeated if a second lead 265 is to be implanted.

While holding lead 265 in place, the needle or sheath is pulled back toexpose contacts of lead 265.

While holding lead 265 in place, interface connector 95 is connected tothe proximal end of lead 265 by opening the hinged lid(s) of connector95 and inserting the proximal end of lead(s) 265 into the access port onthe side of the lid. A verification that the lead 265 is fully insertedcan be performed (e.g. through a visual observation port on the top ofthe hinged lid). The lid is closed (e.g. until a snapping sound isobserved). If a single lead 265 is to be attached, the lead 265 can beconnected to access port A, as shown in FIG. 15M.

In some embodiments, a cable extension can be used to connect lead 265to interface connector 95, such as to position the interface connector95 outside of the sterile field.

A check of connections (e.g. an impedance measurement) can be performed,such as using a programmer 600 (e.g. clinician programmer 600″).

If paresthesia coverage is desired, an appropriate set of stimulationparameters can be identified, such as parameters beginning at arelatively medium pulse width and frequency range. The stimulation canbe delivered, and an increase in amplitude performed while asking thepatient questions (e.g. close-ended questions) to identify thatpatient's perception threshold, a discomfort threshold, and/or an areaof coverage (e.g. paresthesia coverage).

In some embodiments, a fluoroscopic, ultrasonic, and/or other image ofplacement of lead 265 is taken, such as for record-keeping purposes.

If performing a “staged trial”, using a lead 265 to be permanentlyimplanted, interface connector 95 can be detached from lead 265, andanchoring of lead 265 can be performed (e.g. as described hereabove inreference to FIG. 15B). If performing a “temporary trial” using a shortterm implanted lead (e.g. a temporarily implanted lead 265), the excessportion of lead 265 can be coiled and the lead 265 and interfaceconnector 95 can be covered (e.g. with gauze and dressing).

Anchoring of the lead 265 can be performed as described hereabove inreference to FIG. 15B.

Implantation of implantable device 200 can be performed as describedhereabove in reference to FIGS. 15C through 15L.

In some embodiments, one or more implantable devices 200 that have beenimplanted in a patient are explanted. An explantation procedure isdescribed immediately herebelow.

The initial incision and/or lead 265 skin entry site is located. Thisidentification can be performed by palpation, observation of existingsurgical artifacts (i.e., previous sites as indicated by scarring),patient interviews, and/or by using fluoroscopy.

A small midline incision is made at this entry site.

Sutures are cut and removed from the anchor elements 221.

Lead 265 is uncoiled, and pulled on the slack end(s) of the lead 265loop(s), until the distal tip of the lead(s) 265 emerges from theepidural space.

Once the distal end of the lead(s) 265 has been removed from theepidural space, the remaining slack in the lead(s) 265 is pulled inorder to dislodge and remove the implantable device 200.

After the implantable device 200 has been removed, all components can beverified to be intact, and that all previously implanted materials areaccounted for (e.g. removed or intentionally left in place).

The midline incision is closed and covered with gauze and dressing.

Referring now to FIG. 16A-B, a side view of an introducer tool, and amagnified side view of the distal portion of the introducer tool isillustrated, consistent with the present inventive concepts.Implantation tool 65 can comprise an introducer with a tear-away sheath,introducer 6513 shown. Introducer 6513 can include introducer needle6513 a, and tear-away sheath 6513 c. Needle 6513 a can include a beveleddistal end, bevel 6513 d shown. Sheath 6513 c and needle 6513 a compriselengths such that when needle 6513 a is fully inserted into sheath 6513c, bevel 6513 d is completely outside of sheath 6513 c, but within arelatively small distance, D₁, of the distal end of sheath 6513 c, suchas to reduce the likelihood of needle 6513 a entering a target locationof interest (e.g. the epidural space), without the distal end of sheath6513 c also entering that target location. In some embodiments, D1comprises a length of no more than 3 mm, or no more than 2 mm.

Referring now to FIGS. 17A-C, views of an external device and a chargingdevice are illustrated, consistent with the present inventive concepts.FIG. 17A is a perspective view of charger 61, and FIG. 17B is anexploded view of charger 61. FIG. 17C is a view of an external device500 positioned just above a charging position within charger 61. Asdescribed hereabove in reference to FIG. 1, one or more external devices500 can comprise an integrated power supply 570 comprising one or morerechargeable elements, such as a rechargeable battery. Each externaldevice 500 can be configured to engage a charging device, charger 61shown, such that power supply 570 can be recharged. Charger 61 can beconfigured to attach to standard wall AC power, and/or it can include anintegral battery (e.g. a replaceable or rechargeable battery).

Charger 61 comprises housing 6110, which includes top housing 6110 a andbottom housing 6110 b. One or more contacts, contacts 6120, can bepositioning on housing 6110 a and can be configured to electricallyconnect to mating contacts of external device 500, contacts 571, asshown in FIG. 17C. Contacts 6120 are connected to energy-providingcircuitry of charger 61 (not shown), and contacts 571 are connected tocharging circuitry of power supply 570 of external device 500.

Charger 61 can comprise one or more features to maintain the position ofan external device 500 during charging. For example, charger 61 cancomprise flange 6112 which is configured to frictionally engage theperimeter of each external device 500. Alternatively or additionally,charger 61 can comprise recess 6111 which is configured to slidinglyreceive a mating projection of each external device 500, projection 512,each shown in FIG. 17C. In some embodiments, charger 61 comprises two ormore recesses 6111 and external device 500 comprises two or more matingprojections 512. In some embodiments, one or more recesses 6111 ofcharger 61 comprises a projection, and one or more projections 512 ofexternal device 500 comprises a mating recess. Recess 6111 and/matingprojection 512 are positioned and include a geometry (e.g. the “N” shapeshown or other geometry that allows a single rotational orientation ofdevice 500) such that when external device 500 is inserted into charger61, contacts 6120 make contact with the corresponding contacts 571 (e.g.the contacts are vertically aligned when projection 512 mates withrecess 6111).

In some embodiments, charger 61 comprises one or more magnets, magnet6113, which can be configured to magnetically attract a magneticmaterial of each external device 500, such as ferrite disk 557 describedhereabove in reference to FIG. 10. In some embodiments, charger 61comprises one or more magnets 6113 as well as one or more other externaldevice 500 retention features (e.g. flange 6112 and/or recesses 6111described hereabove). Alternatively or additionally, external device 500can comprise mating magnets or other magnetic material (e.g. magneticmaterial which provides correct orientation of contacts 6120 and 571 asdescribed hereabove).

Contacts 6120 and 571 can comprise mating conductive surfaces which makesufficient electrical contact when an external device 500 is properlypositioned in a charger 61. Alternatively, the pair of charging contactscan comprise a standard micro or mini USB port and plug.

Charger 61 can comprise one or more features which cause external device500 to tend to remain properly engaged with charger 61, once in place.For example, flange 6112 (which mates with housing 510) and/or magnets6113 (which attract ferrite disk 557 or other magnetic material ofdevice 500) can be configured to work singly or in combination to causeexternal device 500 to remain in place.

In some embodiments, charger 61 comprises a memory module 6114 whichincludes electronic memory and circuitry configured to record andprocess information related to charge and/or discharge cycles of one ormore external devices 500, as well as record other characteristics, eachof which can be used to predict power supply 570 condition, expectedlongevity and the like, which can be presented to a user or manufacturerof external device 500 (e.g. via a user interface of charger 61, notshown, or other user interface of apparatus 10).

In some embodiments, charger 61 comprises an interface module 6115 whichis configured to interface with a communication network via a wired orwireless communication, such as a communication network selected fromthe group consisting of: cellular service; the Internet; LAN; WAN;computer network; and combinations thereof. In these embodiments,communication with an external device 500 attached to charger 61 can beperformed remotely, such as by a clinician of the patient or amanufacturer of external device 500. The communication can includedownloading of apparatus 10 use information, and/or programming ofexternal device 500 or other apparatus 10 component.

In some embodiments, charger 61 comprises a light, display, or otheruser output component, indicator 6121 shown. Indicator 6121 can comprisea ring-geometry, such as a ring that is positioned between two portionsof housing 6110 as shown in FIG. 17B. Indicator 6121 can comprise one ormore light emitting diodes or other visual indicators, (“LEDs” herein),such as one or more LEDs that change color (e.g. from yellow to orangeto green) to indicate different charging status of the power supply 570of the external device 500 being charged. The LEDs can be positionedunder a ring of translucent plastic or other translucent material.

In some embodiments, charger 61 provides charging energy to power supply570 of external device 500 via wireless transfer of energy (e.g.avoiding the need for contacts 6120 and 571). For example, charger 61and external device 500 can comprise corresponding mating inductivecoils for energy transfer.

Referring additionally to FIG. 17D, a schematic of external device 500charging circuitry is illustrated, consistent with the present inventiveconcepts. External device 500 can be configured to prevent corrosion ofcontacts 571. External device 500 (e.g. controller 550 and/or powersupply 570) can include circuitry (e.g. switching circuitry) configuredas a passivation module (e.g. to prevent or at least reduce corrosion oncontacts 571, such as in the presence of salts, sweat, and the like).When an external device 500 is not operably connected to charger 61(e.g. as detected by external device 500), external device 500 removesthe voltage from being present at contacts 571. As shown in FIG. 17D,when external device 500 is not operably connected to charger 61, Q1(e.g. a transistor) acts as an open switch, and power supply 570 isdisconnected from pins 571. When external device 500 is operablyconnected to charger 61, a voltage is sent on the “detect” pin, whichcloses Q2, which in turn closes Q1, connecting power supply 570 to pins571 (which in turn is connected to charger 61 pins 6120, such as tocharge power supply 570).

In some embodiments, external device 500 is configured to detect anoperable (e.g. successful) connection to charger 61. In theseembodiments, when such a connection is detected, external device 500 canbe configured to shut down (i.e. prevent or at least limit) one or moretransmissions to an implantable device 200 (e.g. a transmissioncomprising transmission of power and/or data to an implantable device200), such as when external device 500 enters a “sleep state” whenattached to a charger 61, to prevent undesired load on power supply 570while charging.

Dual levels of power supply 570 protection can be included, such asprotection circuitry including active circuitry and/or passivecomponents (e.g. a thermal or other resettable fuse). In someembodiments, power supply 570 includes a battery including protectivecircuitry. In some embodiments, external device 500 and/or charger 61includes circuitry to protect power supply 570.

Referring now to FIG. 18, a schematic view of a portion of electronicassembly 255 is illustrated, consistent with the present inventiveconcepts. Electronic assembly 255 comprises portion 255 a which includesvarious components configured to safely and effectively deliverstimulation energy to tissue (e.g. via stimulation elements 260).Electronic assembly portion 255 a includes address-mapped registers thatcan be written directly from external device 500 via a forward-telemetry(FTEL) link, but bandwidth constraints of that link could limit the rateat which stimulation delivered by implantable device 200 can occur. Toovercome this limitation, a digital control structure known as theStimulation Control Table (SCT) can be used. Electronic assembly portion255 a of implantable device 200 can include a configurable state machine(Stimulation Control Table—SCT) that can execute autonomously (e.g.within pre-determined limits) to generate stimulation pulses andmaintain fine grained (e.g. precise) stimulation control of timingand/or amplitude. Being a state machine (as opposed to amicrocontroller) the SCT does not perform computations or makedecisions, and therefore its behavior is deterministic and highlypredictable. Specifically, the following types of parameters can beencoded in the registers and parameters that drive the state table:pulse width; inter-phase gap; and/or inter-pulse gap. The SCT can alsospecify the amplitude of stimulation from a register. Alternatively, theamplitude (and/or timing) can be specified directly in the sequence orit can be provided dynamically.

Layered above a pulse or series of pulses, a “loop” can be used to playa sequence repeatedly (e.g. the SCT includes 4 nested loop levels). Theloops also allow for long sequences of pulses to be played (e.g.delivered) without involvement from external device 500 (therebyreducing telemetry traffic, such as to improve EMI and/or powerefficiency of apparatus 10). With a local clock source, the SCT canexecute commands without any external involvement (e.g. transmissionsfrom external device 500) for significant periods of time (depending onthe stability and accuracy of the clocks of external device 500 andimplantable device 200). Loops can also be used to implement trains ofstimulation pulses and/or bursts of stimulation pulses.

The SCT can include the ability to implement a 1-level sub-routine. Thesub-routine minimizes the usage of program memory (allowing theelectronic circuitry to be smaller). Additionally or alternatively, thesub-routine can allow for complex and/or arbitrary stimulation waveformsto be implemented.

The stimulation amplitude, loop counters and intervals (which can beused for pulse width, inter-pulse gap, and the like) can be modified byexternal device 500 at time of stimulation energy delivery and can beused by the SCT when a subsequent start command is received. In thismanner, significant change can be made to the stimulation patterns withminimal telemetry information needing to be transmitted from externaldevice 500 to implantable device 200. The SCT can trigger measurements.The SCT can check status registers (whose contents can be set fromcomparisons between registers and/or measured quantities) and relayresults to the external device 500 and/or autonomously take action as aresult of the checking performed by the SCT. The SCT can haltstimulation if errors are detected.

Referring additionally to FIG. 19 a block diagram of a TTAP system isillustrated, consistent with the present inventive concepts. Externaldevice 500 can include a digital control structure, a Telemetry TimingAware Peripheral, or “TTAP” herein. The TTAP works with the SCTdescribed hereabove to ensure reliable and efficient operation ofapparatus 10. The TTAP starts the sequence of stored instructions in theSCT program table, where the SCT executes the sequence once and waitsfor further TTAP start commands.

In this manner, the autonomous execution time can be controlled whilestarting a new sequence with minimal telemetry. The TTAP can turn theexternal device 500 on and off to coincide with the stimulation pulsesdelivered by implantable device 200, within a sequence, such as toensure optimal and sufficient power delivery. The TTAP can use acrystal-controlled clock source, and can provide the master time basefor apparatus 10. The rate at which the TTAP issues start commands tothe SCT can determine the overall stimulation rate.

In some embodiments, the stimulation control table can store multiplesets of instructions that can be invoked by the TTAP. Each time the TTAPissues a start command to the SCT, the TTAP can request to start theprevious set of instructions or a start a new set (generally stored at adifferent starting address). Such a configuration can be implemented byimplantable device 200 to efficiently execute complex waveforms (forinstance, combining a train stimulation waveform with a traditionaltonic waveform).

Referring now to FIG. 20A, a schematic view of a power delivery andconsumption arrangement of a stimulation apparatus is illustrated,consistent with the present inventive concepts. Apparatus 10 of thepresent inventive concepts can include arrangement 11 which can beconfigured to enhance reliability of apparatus 10 (e.g. enhancereliability of therapy delivery and/or other functionality). Arrangement11 can be performed by and/or can include one or more componentspositioned within external device 500, implantable device 200, and/oranother component of apparatus 10. In some embodiments, arrangement 11can be configured to reduce power consumption (e.g. enhance battery orother power supply 570 life of an external device 500). In someembodiments, an implantable device 200 receives wireless power from anexternal device 500, and arrangement 11 is configured to both enhancereliability (e.g. enhance reliability of therapy delivery by theimplantable device 200) and reduce power consumption (e.g. enhancebattery life of the external device 500). For example, arrangement 11can be configured to avoid time periods in which insufficient power isreceived by an implantable device 200. Simultaneously, arrangement 11can include one or more algorithms, algorithm 15 (e.g. one or more“optimization” algorithms), which routinely (e.g. continuously and/orintermittently) and/or intelligently adapt to the physical environmentof one or more components of apparatus 10, while external device 500provides power above a minimum threshold required for reliable operation(e.g. reliable stimulation provided to the patient via implantabledevice 200). These algorithms 15 can also adapt to diverse therapyconfigurations (e.g. diverse amounts of stimulation energy beingdelivered) and/or adapt to various implantable device 200 stateconditions, and the algorithms 15 can manage transitions in theseconfigurations and conditions.

Each implantable device 200 is desired to be relatively small, andtherefore can have limited energy storage capacity (e.g. limited energystorage capacity of energy storage assembly 270). When there is a changein power transfer (e.g. a sudden change that can occur with patientmotion) and/or there is a change in power consumption (e.g. due to achange in delivery of stimulation energy), arrangement 11, via algorithm15, can be configured to rapidly adapt so that power delivery from anexternal device 500 to the implantable device 200 remains sufficient forsafe and reliable operation.

Apparatus 10 can include multiple mechanisms for adjusting powerdelivery between an external device 500 and an implantable device 200.For example, a first mechanism can adjust the amplitude of powertransmitted by external device 500 to change the output power of thetransmission signal (e.g. an RF signal). Alternatively or additionally,a second mechanism can turn the power transmitted by external device 500on and off, such as via a duty cycle that includes a ratio of “on time”versus “off time” that is set and/or adjusted by an algorithm 15 (e.g.an optimization algorithm of arrangement 11, such as an algorithm 15 ofexternal device 500). Power can be wasted if energy stored onimplantable device 200 reaches a maximum value (e.g. where furthercharging can't occur) and external device 500 continues to deliverpower. This energy storage maximum can be limited by an acceptable inputvoltage of a rectifier (e.g. rectifier 232) of implantable device 200,such as when the rectifier is operating as a charge pump, providing avoltage multiplication of an input voltage of an antenna (e.g. antenna240) of implantable device 200. Implantable device 200 can include otherelectronic componentry that limits a maximum voltage for energy storage(e.g. the circuitry includes a voltage clamp that prevents an excessivevoltage from damaging an electronic component).

Arrangement 11 can be configured to perform duty cycle modulation ofpower transferred by an external device 500 based on an amplifier ofexternal device 500 being more efficient when charging at particularpower levels (e.g. high-power levels) that do not saturate circuitry ofimplantable device 200 and/or do not cause reduced efficiency byexceeding an optimal input voltage of a rectifier 232 of implantabledevice 200. As described hereabove, power can be delivered in bursts viaduty cycle modulation which can deliver power before and afterstimulation pulses (e.g. in a symmetric pattern). Power delivery beforestimulation can prevent a significant voltage drop (e.g. of energystorage assembly 270) when implantable device 200 transitions fromoperating at a quiescent current to a state in which device 200 isdelivering stimulation energy to tissue. If sufficient energy isavailable, boosting circuitry of implantable device 200 can operate witha minimum conversion ratio, which increases efficiency and maximizes theinstantaneous power that implantable device 200 can deliver (e.g. powerrelated to delivering stimulation energy to tissue). Power delivery todevice 200 after stimulation delivery by device 200 can replenish energyused during stimulation, and it can reduce impact of disturbances inpower transfer. Duty cycle modulation can be applicable to idle (e.g. nostimulation) modes and/or lower frequency stimulation modes (e.g.stimulation below approximately 1.5 kHz or below 1 kHz) of implantabledevice 200. When varying power transfer with duty cycle, an optimizationalgorithm 15 of arrangement 11 can measure stored energy in implant 200(e.g. stored in energy storage assembly 270), for example a measurementperformed once every stimulation period (e.g. a period of time in whichone or more forms of stimulation energy is delivered), and algorithm 15can adjust the duty cycle based on an analysis of energy requirementsfor that stimulation period. Energy measurements (e.g. voltagemeasurements) can be taken (e.g. immediately) prior to a firststimulation pulse in the stimulation period, a point in which the storedenergy can be high. To measure a target energy level effectively, atarget voltage of energy storage assembly 270 can be set slightly belowthe maximum allowed value. An optimization algorithm 15 can determine atarget (maximum) value of energy storage by increasing (or maximizing)the duty cycle for a (short) time period, and subsequently measuring theenergy level. Alternatively or additionally, the energy level can beoccasionally increased over time until a constant error is observed(e.g. a maximum has been achieved), which also indicates a limit hasbeen reached. The target energy level used by algorithm 15 can then beadjusted slightly below the maximum thereby allowing optimized energystorage with the described control loop (also referred to as “trackingloop” or “feedback loop” herein). During optimization, the duty cycle ateach stimulation cycle can be fed to a lowpass digital filter (e.g. afilter of controller 550) with a time constant that is much slower thanthe stimulation rate, and the output of this filter can be sampled afterseveral time constants. The filtered value is the average duty cycleduring the sampling period. If the average duty cycle is too high, thenthe output power of the transmitter 530 of external device 500 can beincreased. If the average duty cycle is too low, then the output powerof the transmitter 530 of external device 500 can be decreased.Controlling the average duty cycle can allow the power transmitter 530to operate at an optimized point, and it can allow a feedback loop ofarrangement 11 to quickly raise duty cycle in response to a disturbancein power.

Arrangement 11 can utilize duty cycle modulation when there are multiplestimulation pulses delivered in a stimulation period. The powertransferred from external device 500 to implantable device 200 can beallocated based on energy of stimulation pulses, as well as when thepulses occur in the stimulation period. With multiple stimulationpulses, the periodic measurement of available energy in implantabledevice 200 can be performed immediately prior to the stimulation pulsedelivering the greatest energy. In other words, if a stimulation periodconsists of multiple pulses, a timing of a stimulation period can bedefined such that the largest energy pulse is the first pulse.

Arrangement 11 of FIG. 20A demonstrates the available energy over time,as power is transmitted and used by implantable device 200. As describedabove, power transmission from external device 500 is represented by twoparameters, the amplitude of the transmission signal, and the duty cycleof transmission. Power consumption by each implantable device 200comprises: energy delivered during stimulation; energy deliveredperforming other functions (e.g. sensing functions, data transmissionfunction, and/or other functions); and/or quiescent energy required byimplantable device 200 during minimal operation. Integrating the sum ofpower used over time determines energy to be stored in implantabledevice 200, which can have one or more limits as described hereabove. Ifthe energy storage element of assembly 270 is a capacitor or battery,this limit will be reflected as a limit in the voltage as describedhereabove. Circuitry of implantable device 200 can also have a maximumoperating voltage that limits the energy that can be stored, also asdescribed hereabove.

The power transfer efficiency between an external device 500 and animplantable device 200 represents the ability of external device 500 toprovide energy to the implantable device 200 and also represents thequality of the wireless link between the two devices. This efficiencycan vary over time (such as with patient motion and/or changes inenvironment), and the efficiency can be tracked by arrangement 11 suchthat the implantable device 200 neither loses power (power leveldecreases to a point below a minimum threshold, such as to cause aninterruption in stimulation delivery and/or other implantable device 200operation), nor is excessively charged (wasting power).

When apparatus 10 reaches a steady state, the duty cycle of powertransmission can be stable. For example, over a (repeated) period oftime of a control loop (a control loop managed by an optimizationalgorithm 15 of arrangement 11), the energy transmitted from externaldevice 500 to implantable device 200 can be approximately equal to thesum of: the energy for therapy (e.g. stimulation energy delivered); theenergy required for other functions of implantable device 200; and thequiescent energy requirements of implantable device 200. As a result,the available energy of implantable device 200 will rise and fall thesame amount during each time period. Furthermore, the maximum energywill be maintained at a value slightly lower than a limit (e.g. amaximum voltage).

In some embodiments, algorithm 15 only modulates duty cycle of the powertransmissions of external device 500. In some embodiments, algorithm 15modulates both duty cycle and the voltage (e.g. to modulate the averagepower being transmitted). These modulations can be performed in relationto the current stimulation parameters to be delivered by implantabledevice 200.

Referring now to FIG. 20B, a schematic view of a power delivery andconsumption arrangement of a stimulation apparatus is illustrated,consistent with the present inventive concepts. Apparatus 10 of thepresent inventive concepts can include arrangement 12 which can beconfigured to enhance reliability of apparatus 10 (e.g. enhancereliability of therapy delivery and/or other functionality). Arrangement12 can control duty cycle of power transfer between an external device500 and an implantable device 200. Arrangement 12 can be performed byand/or can include one or more components positioned within externaldevice 500, implantable device 200, and/or another component ofapparatus 10. Arrangement 12 includes arrangement 11 as shown, such asarrangement 11 described hereabove in reference to FIG. 20A. Arrangement12 comprises a “block” (e.g. electronic feedback circuitry) configuredto calculate an error (also referred to as a “loop error”) between asetpoint energy level and a measured energy level. The calculated erroris provided to a Proportional Integrator (PI) controller (e.g. a PIcontroller that includes a derivate control) which determines a powertransmission duty cycle based on the calculated error. A highproportional path gain allows the control loop of arrangement 12 torespond quickly to disturbances (e.g. power transfer disturbances),thereby providing reliability in implantable device 200 function (e.g.uninterrupted delivery of stimulation energy). Periodically updating theamplitude of power transfer provided by external device 500 can beperformed to keep the average duty cycle low, thereby providing a largedynamic range in the duty cycle, such that the proportional path has therequired dynamic range to quickly respond to disturbances. The integralpath drives the steady state error to zero, thereby providing theoptimized resilience to disturbance and optimized efficiency.

The setpoint can be determined dynamically. The error and/or gain can beasymmetric, and it can be adjusted based on previous measurements.Applying the charge time can include allocation over multiplestimulation pulses, each with different amplitudes and/or timings (e.g.timings such as pulse width timing and/or burst duration timing). Powertransfer from external device 500 to implantable device 200 can beperiodically adjusted to maintain a duty cycle with the desired dynamicrange.

Arrangement 12 can manage significant disturbances by maintaining anenergy setpoint that is close to the energy storage limit of energystorage assembly 270. The setpoint can be determined by periodicallydetermining the energy storage limit itself, such as by increasing theduty cycle limit to the maximum for a short period. The energy storagelimit can be measured, and the energy setpoint can be set to a valueslightly below the measured maximum. If apparatus 10 is in asteady-state mode and power transfer efficiency suddenly increases, theavailable energy can rise and reach the limit. The measured error willtherefore be limited to a value slightly above the setpoint, and,response could be slow causing power to be wasted. This undesiredperformance can be mitigated by raising the loop gain in response toconsecutive negative errors, or with asymmetric gain based on thedirection of the error. If power transfer is high and the therapy at alow level (e.g. a low energy delivery level), the minimum duty cyclerequired for the energy storage measurement can be greater thannecessary, and power could be wasted. Conversely, if power transfer istoo low, then the average duty cycle can be large, and apparatus 10 maynot have the dynamic range to respond to a disturbance. Therefore, itcan be desirable to keep the duty cycle of power transmissions fromexternal device 500 within a controlled range, such as a range betweenapproximately 20% and 40%, or between 25% and 33%. This range can bemaintained by lowpass filtering the duty cycle with a first orderdigital filter, and sampling the output every several time-constants,such as every 4 time-constants. The time constant of the digital filtercan be approximately the same as the stimulation period or longer thanthe stimulation period in order to behave as a lowpass filter. If theduty cycle is out of this range, power transfer amplitude can beadjusted accordingly.

Referring now to FIG. 21, a schematic view of a back-telemetry circuitof an implantable device 200 is illustrated, consistent with the presentinventive concepts. Controller 250 of implantable device 200 can includeback-telemetry module 251 as shown in FIG. 21. Back-telemetry module 251can be configured to provide dynamic threshold and polarity.Back-telemetry module 251 can include redundant bit encoding.

In some embodiments, controller 250 comprises a dynamic receiver. Thedynamic receiver can include a dynamic mechanism for threshold andpolarity. The receiver can be configured to determine thresholds ofwidth of pulses, and/or polarity of pulses, dynamically. Controller 250can receive a series of pulses, and it can decode the patterndynamically. The dynamic receiver can determine levels (e.g. l's and0's) based on known parameters, such as to calibrate the receiver.

In some embodiments, back-telemetry from implantable device 200 toexternal device 500 may comprise adjusting an impedance connected toantenna 240 of the implantable device 200. The external device 500 candetect these changes in impedance to recover (i.e. receive and decode)information from implantable device 200. The impedance changes can beperformed in short pulses, with information encoded in the length of thepulses. To maintain a balance in timing and in the average amplitude, adata bit can be comprised of both a short and a long pulse. For example,a “0” bit can be represented as a short pulse followed by a long pulse,and a “1” bit could be represented by a long pulse followed by a shortpulse. In this way, both the “0” and the “1” bit have an equal length oftime and the same average signal level, (i.e. both 0 and 1 have equalhigh periods and low periods). This combination also offers redundancyto improve error detection and recovery.

In some embodiments, the beginning of a data transmission (e.g. aresponse) from an implantable device 200 can be represented by a “sync”mark, which can comprise a combination of short and long pulses thatwould not be possible in a normal data stream. The data sequence can bea fixed length that is known a priori so that the expected number ofpulses is known. Knowing the exact number of expected pulses can aid inapparatus 10 detecting and recovering from errors, for example in case apulse is missed (e.g. not properly detected by external device 500).Additionally, since each data bit is an equal length of time and thedata length is known, the exact position of errors in the data can bedetermined if they occur. Since distortion is most likely at thebeginning of a pulse sequence, implantable device 200 can be configuredto provide a preamble (e.g. a sequence of dummy data) that precedes theactual data and the sequence can be decoded by external device 500 inreverse order, from the final pulse towards the first. If the datalength is known, external device 500 can stop decoding once all the datais recovered, ignoring the possibly distorted pulses at the start of thesequence.

In some embodiments, external device 500 can recover these pulses andconvert them to a digital signal using an analog filter with acomparator included in external device 500 (e.g. included in controller550). If the encoding described above is used to maintain a constantaverage signal regardless of the content of the data, then thecomparator can compare the average to the envelope of the recoveredsignal to perform this conversion. Since this signal is detected from animpedance change, it is possible that the pulses will be recovered aseither increases in the signal level or decreases in the signal leveldepending on the characteristics of the link, such as transmitted poweror coupling. External device 500 can dynamically determine the polarityof the pulses by reading a known value received from the implantabledevice 200, decoding the response, and adjusting the polarity based onthe result (e.g. calibrating external device 500 based on the result).Additionally, it is possible that the signal will be distorted whenrecovered by external device 500, and this distortion may also changebased on the transmitted power level and coupling. This distortioneffect can result in the durations of the pulses changing as the deviceoperates normally. To correctly recover this data, the external device500 can accumulate the durations of all the pulses in the response anddivide by the number of pulses, to determine the average pulse width.Then, external device 500 can use this average pulse width todifferentiate between short and long pulses. By doing this computation,external device 500 can dynamically adjust the decoding threshold toachieve optimized recovery of the data.

In the illustrations described herebelow in reference to FIGS. 22A-F,various arrangements of one or more leads 265 including sets ofstimulation elements 260 (e.g. electrodes) are shown. In the figures,the boxes labeled Is represent series impedance related to theassociated stimulation element 260. The boxes labeled IT representtissue impedance between the two adjacent stimulation elements 260.

Referring now to FIG. 22A, a schematic view of an implantable device 200comprising two leads 265 is illustrated, consistent with the presentinventive concepts. Each lead 265 comprises multiple stimulationelements 260 (eight shown for each lead 265). In some embodiments,implantable system 20 is configured without a monopolar return path,such as when stimulation energy is delivered in a bipolar mode betweenpairs of stimulation elements 260 (e.g. without housing 210 of animplantable device 200 functioning as a current return path). Duringstimulation, certain stimulation elements 260 (e.g. electrodes) areconfigured as anodes, and certain stimulation elements 260 areconfigured as cathodes. Implantable device 200 comprises a currentsource that is connected to the cathodes while the anodes are connectedto a system ground of implantable device 200 (e.g. to complete theelectrical stimulation circuit). It is of interest to know the networkof impedances between the various stimulation elements 260 (e.g. betweenthe cathodes and the anodes). These impedances can be determined if theimpedance of each individual stimulation element 260 is known. In orderto measure individual stimulation element 260 impedances (e.g. electrodeimpedance), a “pseudo-monopolar” connection can be made, as describedherebelow in reference to FIG. 22B.

Referring now to FIG. 22B, a schematic view of an implantable device 200including multiple stimulation elements 260 configured to perform animpedance measurement associated with a first stimulation element 260′is illustrated, consistent with the present inventive concepts.Implantable device 200 and its stimulation elements 260 have beenimplanted in a patient, and electrical pathways in the tissue betweenthe elements 260 are shown. In a first step, stimulation element 260′ isconfigured as a cathode, and all other “remaining” stimulation elements260 (e.g. in the same lead 265) are assigned as anodes, where theseremaining stimulation elements 260 are connected in parallel to thesystem ground. In doing so, the effect of individual remainingstimulation elements 260 shown including within the box “B” is minimized(e.g. allowing a “pseudo-monopolar” calculation to be made). A currentsource (e.g. of controller 250) drives a current pulse through thisnetwork and the resulting voltage pulse is measured at stimulationelement 260′ with respect to system ground. By sampling the voltagepulse close to the pulse rising edge and using Ohm's law, anapproximation of impedance of stimulation element 260′ is obtained.

Similarly, the impedance of all other stimulation elements 260 ismeasured. A similar process can be repeated for additional sets ofstimulation elements 260 (e.g. additional stimulation elements 260included on additional leads 265).

The stimulation element 260 impedance (e.g. electrode impedance)measured using this method is an “upper bound” on the actual impedancevalue. This bounded value is desirable for calculating current sourcecompliance voltage requirements.

Referring now to FIG. 22C, a schematic view of an implantable device 200including multiple stimulation elements 260 configured to perform acheck for undesired shorts is illustrated, consistent with the presentinventive concepts. In the embodiment of FIG. 22C, an undesired shortexists between stimulation element 260′ and stimulation element 260″ asshown. When a current source (e.g. of controller 250) delivers a currentpulse to element 260′, the voltage developed at stimulation element 260′with respect to system ground is close to zero (e.g. below a threshold)as the path of least resistance is from element 260′ to element 260″ tosystem ground. This current pulse results in a very small impedancemeasurement on stimulation element 260′ (e.g. as described hereabove inreference to FIGS. 22A-B). Similarly, when measuring impedance ofstimulation element 260″, a very small impedance value is also measured.These two impedance measurements are indicative of a short between thetwo elements 260′ and 260″. In general, if such an impedance measurementresults in a small value at any stimulation element 260, it isindicative that the stimulation element 260 is shorted to anotherstimulation element 260 (e.g. another element 260 of the same lead 265).Such a check for shorts can be performed during a manufacturing process,or at any time (e.g. just prior to and/or after implantable device 200is implanted in the patient).

Referring now to FIG. 22D, a schematic view of an implantable device 200including multiple stimulation elements 260 configured to perform acheck for undesired shorts is illustrated, consistent with the presentinventive concepts. In the embodiment of FIG. 22D, an undesired shortexists between stimulation element 260′ and stimulation element 260″ asshown. A multiplexor, such as an analog multiplexor, MUX1 shown, can beused to attach any and/or all of stimulation elements 260 to ground(sequentially and/or simultaneously). To determine if a stimulationelement 260 (e.g. stimulation element 260′ shown) is shorted to anyother stimulation element 260, a current source (e.g. of controller 250)is connected to stimulation element 260′ and the resulting voltage ismeasured on all other stimulation elements 260. If there is no short (orother electrical connection path) between stimulation element 260′ andall other elements 260, then no voltage shall be observed at thoseelements 260 (e.g. with respect to system ground). If a voltage isobserved (e.g. a voltage above a threshold is observed), then a shortbetween element 260′ and some other element 260 is determined to bepresent by implantable device 200. In the illustration, a pulsegenerated by a current source connected to stimulation element 260′ isobserved on all other stimulation elements 260 (e.g. electrodes) due toa short between stimulation element 260′ and 260″. During use, such anobserved pulse is indicative that stimulation element 260′ is shorted tosome other stimulation element 260.

Referring now to FIG. 22E, a schematic view of an implantable device 200including multiple stimulation elements 260 configured to perform acheck for undesired open circuits is illustrated, consistent with thepresent inventive concepts. In the embodiment of FIG. 22E, an undesiredopen circuit exists at stimulation element 260′ as shown. In adiagnostic test, a current source (e.g. of controller 250) attempts todeliver current through a stimulation element 260. If an open circuit ispresent, the voltage observed on that stimulation element 260 would behigh. The high voltage is interpreted as a high impedance per theimpedance measurement test described hereabove in reference to FIG.22A-B.

Referring now to FIG. 22F, a schematic view of an implantable device 200including multiple stimulation elements 260 configured to measureindividual stimulation element impedance is illustrated, consistent withthe present inventive concepts. FIG. 22F illustrates an exampleelectrical connection used to perform an impedance measurement method.In this configuration, a current source is connected to one stimulationelement, stimulation element 260′ shown, and the return path iscompleted using another stimulation element, stimulation element 260″shown. A voltage pulse resulting due to a current pulse generated by thecurrent source is measured at stimulation element 260′. By sampling thevoltage pulse close to the rising edge of the pulse, an estimate of thesum of individual impedances R0 and R1 is obtained. If R01 indicates thesum, then R01=R0+R1. Similarly, estimates for two other pairs can beobtained. For example, R12=R1+R2; and R02=R0+R2. These equations can besolved simultaneously to calculate the unknown impedance values: R0, R1and R2. Similarly, all the remaining individual impedances can becalculated. Alternatively or additionally, the impedance measurementmethod described in FIG. 22A-B can be used as a pre-processing step tofind out if there are open electrodes (stimulation elements 260) in thelead 265, such that these elements can be omitted from the set ofequations to be solved simultaneously. This method can limitinaccuracies that may result due to including open electrodes in the setof measurements. In some embodiments, estimates of several pairs can beanalyzed together and the large set of equations solved using linearalgebraic methods.

Referring now to FIG. 23, a graph of an amplitude modulation scheme isillustrated, consistent with the present inventive concepts.Transmissions between an external device 500 and one or more implantabledevices 200 can comprise a modulated transmission signal, such as anamplitude modulated transmission signal as shown in FIG. 23. In someembodiments, the modulation depth is relatively “shallow” (e.g. amodulation depth less than 20%, or less than 5%). Such shallowmodulation depths provide numerous advantages, such as reduced emissions(e.g. for regulatory compliance), improved efficiency, and/or reducedinstantaneous power transfer. External device 500 can comprise anelectronic potentiometer (e.g. controller 550 comprises the electronicpotentiometer) that allows adjustment of the modulation depth (e.g. byadjusting the input voltage driving a gate of an amplifier providing thetransmission signal, such as an amplifier which is operating atsaturation). In some embodiments, the electronic potentiometer isadjusted in manufacturing of external device 500, such as using a set ofvalues corresponding to a power amplifier setting. Alternatively oradditionally, the electronic potentiometer can be adjusted in use (e.g.in the clinical setting). For example, controller 550 can includefirmware that determines a desired modulation depth, such as to optimizeefficiency of transmissions without sacrificing reliability oftransmissions. Such adjustment in the clinical setting can minimizecommunication errors, such as when the associated implantable device 200has been implanted relatively deep under the surface of the skin, suchas when a component of an external device 500 (e.g. ferrite or othercomponent) and/or implantable device 200 has been damaged or isotherwise compromised.

Referring now to FIGS. 24A-B, top views of an external device 500positioned on a patient in a first orientation, and a secondorientation, respectively, is illustrated, consistent with the presentinventive concepts. In FIG. 24A, external device 500 is positioned in afirst orientation, on a patient's skin above an implantable device 200that has been implanted in the patient, and transmissions (e.g. powerand/or data transmissions) between the two devices can occursuccessfully and efficiently. In some embodiments, external antenna 540of external device 500 is positioned at a skin location that isrelatively centered, “concentric” herein, with implantable antenna 240of implantable device 200. In these embodiments, antennas 540 and 240can be positioned within housings 510 and 210 respectively, such thatpositioning housing 510 at a skin location that is relatively centeredwith the position of housing 210, will in turn, properly positionantenna 540 with antenna 240 (e.g. to optimize transmissions between theantennas). External device 500 can be configured to be positioned in asecond orientation, different than the first orientation, withoutreducing transmission quality between devices 500 and 200. For example,external device 500 can be configured to be rotated but similarlyconcentrically positioned over implantable device 200, such as whenrotated 180° as shown in FIG. 24B, without adversely affectingtransmission quality. Apparatus 10 can be configured to perform thetransmissions relatively equally in different orientations, such as whenefficiency of transmissions from external device 500 to implantabledevice 200, from implantable device 200 to external device 500, andboth, are relatively unaffected by the different orientations (e.g.different rotational orientations of device 500, with antenna 540 and/orhousing 510 proximate the patient's skin surface and relatively centeredover antenna 240 and/or housing 210). Avoiding the need to achieve aparticular orientation (e.g. a particular rotational placement ofexternal device 500 on the patient's skin), greatly simplifiesattachment of external device 500 to the patient's skin by a user (e.g.by the patient).

For example, antennas 240 and/or 540 can comprise a construction, andeach can be oriented in implantable device 200 and/or external device500, respectively, in a way that minimizes the impact of a particularorientation of external device 500 to an implanted implantable device200. In some embodiments, antennas 240 and/or 540 comprise loopantennas, such as rectangular loop antennas. In some embodiments, theratio of the size of external antenna 540 compared to the size ofimplantable antenna 240 is relatively high, such that the impact oforientation variations is minimized, such as a ratio of at least 2:1,4:1, and/or 6:1.

Referring now to FIG. 25A, a schematic view of a reconfigurablestimulation block (RSB) portion 255 b of electronic assembly 255 ofimplantable device 200 is illustrated, consistent with the presentinventive concepts. RSB 255 b can comprise one or more current sources,such as a high-side current source and a low-side current source. In theembodiment shown in FIG. 25A, there is only one (high-side) currentsource, and the current return path is to ground through the closing ofswitch S_(L) shown, which is connected to VB (versus a return paththrough a low-side current source). In active charge recovery (bipolarstimulation), current direction is reversed by changing the MUXA andMUXB settings. For example, during a stimulation phase, E1 is connectedto VA and E0 is connected to VB, whereas during a recovery phase, E1 isconnected to VB and E0 is connected to VA. Current source and groundswitch settings remain the same in both phases. As compared to anarrangement with both a high-side and a low-side current source,low-side current source and high-side supply switches have beeneliminated.

Referring now to FIG. 25B, a diagram of a control input sequence isillustrated, consistent with the present inventive concepts. Use of thecontrol signals of FIG. 25A are shown in FIG. 25B. Current flows throughswitch S_(D) when any bits of ‘rsbx_isrc_sel<3:0>’ is asserted and when‘rsbx_gate_reg’ (sync signal) is not asserted. This time period needs tobe small in order to minimize the power lost during the “dump phase”(e.g. when current is diverted through switch S_(D) and resistor R_(D)shown). The RSB 225 b circuitry is designed to be operated with thistime period being as small as 1 μs. ‘Rsbx_swselb’ & ‘rsbx_ss_sel’ can beasserted at the same time as ‘rsbx_isrc_sel’ in order to shortenstimulation setup time. As show in FIG. 25B, these signals need not bede-asserted in the region between the two phases of the stimulation.

In some embodiments, a DC blocking capacitor is included in RSB 225 b,capacitor C_(DC). In the embodiment shown in FIG. 25A, the DC-blockingcapacitor C_(DC) is not included, instead each stimulation element 260(e.g. electrode) has a DC-blocking capacitor between each MUXA/B outputterminal and the corresponding stimulation element 260 (tissueconnection). There can be 16 DC-blocking capacitors (e.g. for spinalcord stimulation); and these capacitors can be shared between all RSB255 b's. A single set of discharge switches (e.g. transistors configuredas switches) can be connected between the VA and VB nodes.

Referring additionally to FIG. 25C, a schematic view of another portionof electronic assembly 255 is illustrated, portion 255 c, consistentwith the present inventive concepts. Given that the stimulation currentpath contains switched capacitive elements, both in the interfacebetween stimulation elements 260 and tissue, and in the form ofDC-blocking capacitors, it is possible for chip nodes (e.g. connectionpoints of an integrated circuit) to go below the ground rail (e.g. belowa ground level of voltage associated with the integrated circuit) asfollows. During the stimulation phase, a first terminal of the seriescapacitor string is charged positively with respect to the otherterminal of the capacitor. During the recovery phase, the first terminalis connected to ground and thus the other terminal of the capacitor ischarged negatively with respect to the first voltage (e.g. the voltageof the second terminal can go below ground, which can result inundesired current flow). This configuration can forward-biasESD-protection and parasitic bulk diodes of the output circuits, and itcan cause the recovery current to be uncontrolled. This lack of control,in turn, can cause charge-balance problems if the external DC-blockingcapacitors are not included, and/or it can result in inaccuratestimulation current being delivered. In some embodiments, these issuesare solved by adding series resistors between the ground switch andstimulation outputs during the recovery phase. As current flows throughthese resistors they create a voltage drop, which raises theotherwise-negative terminal to a desired level above ground potential.Typically, soft switches (e.g. transistors T₀ through T₁₁ shown) areenabled during the start of the recovery phase (e.g. to avoid undesiredcurrent flow, such as undesired current flow in the integrated circuit),and then switched out (e.g. disabled) as the capacitor(s) discharge, toavoid loss in stimulation compliance. Example architecture of the softswitches, and example resistance values, are listed below.

Soft Switch Resistance (Transistor) rsbx_ss_sel Value 000000000000 — T₀ 000000000001 200 T₁  000000000010 200 T₁  000000000100 200 T₃ 000000001000 200 T₄  000000010000 500 T₅  000000100000 800 T₆ 000001000000 1.5 k T₇  000010000000 2.7 k T₈  000100000000 5.4 k T₀₉001000000000   8 k T₁₀ 010000000000  15 k T₁₁ 100000000000  50 k

Referring now to FIG. 26A-C, schematic views of a test fixturearrangement for testing electronic assembly 255 is illustrated,consistent with the present inventive concepts. Test fixture 97 isconstructed and arranged to perform one or more tests on electronicassembly 255 of an implantable device 200. In a first embodiment, asdescribed in reference to FIG. 26A, test fixture 97 is configured toperform a test on electronic assembly 255 when implantable device 200 isin a partially assembled state, when electrical access points onelectronic assembly 255 are accessible to test fixture 97. In analternative or additionally second embodiment, as described in referenceto FIGS. 26B-C, test fixture 97 can be configured to perform a test onan electronic assembly 255 by connecting with one or more stimulationelements 260 (e.g. electrodes) and/or other stimulation energy-providingelectrical access points outside of housing 210. In other words, testfixture 97 can be configured to perform a test on electronic assembly255 when implantable device 200 is in a fully manufactured state (e.g.in a state ready for shipment to a customer and including a pre-attachedlead 265 and/or an attachable lead 265). In the fully manufacturedstate, a ground pathway of electronic assembly 255 may not be availableto perform a test in which electronic assembly 255 and test fixture 97share a common ground.

Referring now to FIG. 26A, as described hereabove, test fixture 97 canbe configured to test electronic assembly 255 while implantable device200 is in a partially assembled state. Test fixture 97 includesconnection point 9701 a which is shown having been attached (e.g. by anemployee of the manufacturer of electronic assembly 255) to electricalconnection point 256 a of electronic assembly 255, and connection point9702 is shown similarly having been attached to electrical connectionpoint 257 of electronic assembly 255 (e.g. creating a common groundbetween electronic assembly 255 and test fixture 97). Electricalconnection point 256 a is part of a first electrical signal pathway(e.g. wire or trace) that is configured to deliver stimulation energy toa first stimulation element 260 a (e.g. an electrode, not shown).Electrical connection point 256 a can be positioned “downstream”, asshown, of a capacitor in series with the first electrical signalpathway, capacitor C1, such that test fixture 97 can test the leakagecurrent of capacitor C1. For example, during a test of the first signalpathway, an ASIC of electronic assembly 255 connects the upstream sideof capacitor C1 to a switch, switch S1, by activating a multiplexor, MUX1, to make the specific connection between C1 and S1. The ASIC alsocloses switch S1 such that the upstream side of capacitor C1electrically connects to a ground pathway of electronic assembly 255, asshown. During this test of the first signal pathway, test fixture 97electrically connects connection point 9701 a to an ammeter, M1, whichis attached to a voltage supply, DC voltage supply V_(CC) shown. In thisfirst connection configuration shown, ammeter M1 measures any leakagecurrent of capacitor C1. Subsequent tests of all remaining capacitors C2thru C_(N) can be performed. Connection points 9701 b thru 9701 n oftest fixture 97 are attached to corresponding connection points 256 bthru 256 n of electronic assembly 255 (e.g. connections which are madesingly or collectively prior to each test). Sequential tests of eachcapacitor C2 thru C_(N) can be performed when MUX 1 sequentiallyconnects each capacitor C2 thru C_(N), to switch S1 (e.g. which isclosed and connected to the ground pathway of assembly 255), and amultiplexor of test fixture 97, MUX 2, simultaneously and respectivelyconnects each connection point 9702 b thru 9702 n to voltage supplyV_(CC). In some embodiments, electronic assembly 255 is configured toprovide stimulation energy to multiple stimulation elements 260 (e.g.electrodes), such as 4, 6, 8, 12, and/or 16 electrodes, such as whenelectronic assembly 255 comprises 4, 6, 8, 12, and/or 16 signalpathways, each including a capacitor as shown in FIG. 26A.

Referring now to FIG. 26B, as described hereabove, test fixture 97 canbe configured to test electronic assembly 255 while implantable device200 is in a fully assembled state (e.g. a state in which a groundpathway of electronic assembly 255 may not be available to connect totest fixture 97). Test fixture 97 includes connection point 9701 a whichis shown having been attached (e.g. by an employee of the manufacturerof implantable device 200 during a final test, or by a clinician orhealthcare provider at a time proximate implantation of implantabledevice 200) to electrical connection point 256 a of electronic assembly255. Electrical connection point 256 a is part (e.g. the end portion) ofa first electrical signal pathway (e.g. wire or trace) that isconfigured to deliver stimulation energy to a first stimulation element260 a (not shown). In some embodiments, electrical connection point 256a comprises a portion of first stimulation element 260 a. Electricalconnection point 256 a can be positioned “downstream”, as shown, of acapacitor in series with the first electrical signal pathway, capacitorC1, such that test fixture 97 can test the leakage current of capacitorC1. For example, during a test of the first signal pathway, an ASIC ofelectronic assembly 255 connects the upstream side of capacitor C1 to aswitch, switch S1, by activating a multiplexor, MUX 1, to make thespecific connection between C1 and S1. The ASIC also closes switch S1,which is connected to an input of another multiplexor of electronicassembly 255, MUX 3 as shown. The ASIC activates MUX 3 such that theupstream side of all of the other capacitors, C2 through CN, areconnected to switch S1 as shown (e.g. shorted together). During thisconnection arrangement, MUX 2 of test fixture 97 connects connectionpoint 9701 a to ammeter M1. Test fixture 97 further includes anothermultiplexor, MUX 4 shown, which connects each of connection points 9701b thru 9701 n to the ground of test fixture 97 (e.g. shorts each ofconnection points 9701 b thru 9701 n to test fixture 97 ground). In thisconnection scheme of electronic assembly 255 and test fixture 97,voltage provided by supply V_(CC) is presented at the downstream side ofcapacitor C1. Any leakage current that passes through capacitor C1,subsequently leaks through all of the remaining capacitors C2 thruC_(N), such that any leakage current measured by ammeter M1 is dominatedby the leakage current through capacitor C1. The effective circuit andcurrent path of testing a first stimulation pathway (including capacitorC1), is shown in FIG. 26C. Subsequent tests of all remaining capacitorsC2 thru C_(N) can be performed, such as in a similar fashion to thatdescribed hereabove in reference to FIG. 26A. For example, in a test ofany capacitor C_(N), MUX 1 connects switch 1 to the upstream side ofcapacitor C_(N), and MUX 2 shorts each of the upstream sides of theremaining capacitors together. Test fixture 97 connects connection point9701 b to ammeter M1, and fixture 97 shorts the remaining connectionpoints 9701 together and to the ground of test fixture 97. In someembodiments, electronic assembly 255 is configured to providestimulation energy to multiple stimulation elements 260 (e.g.electrodes), such as 4, 6, 8, 12, and/or 16 electrodes, such as whenelectronic assembly 255 comprises 4, 6, 8, 12, and/or 16 signalpathways, each including a capacitor as shown in FIG. 26B.

Referring now to FIG. 27A-C, a series of views of stimulation waveformsare illustrated. consistent with the present inventive concepts. In FIG.27A, a tonic stimulation waveform for delivery to a single location(e.g. a single nerve or other continuous tissue volume location) isillustrated. In FIG. 27B, a tonic stimulation waveform for multiplelocations (e.g. two to five discrete tissue volume locations capable ofbeing stimulated by multiple stimulation elements 260 of a single lead265 and/or multiple leads 265) is illustrated. In FIG. 27C, a tonicsequence stimulation waveform is illustrated.

When tonic stimulation is to be provided by apparatus 10 (e.g. to asingle location), implantable device 200 can deliver a monophasic pulseas shown in FIG. 27A. When stimulation of a single location is provided,implantable device 200 can perform current steering (e.g. per electrodeparameters).

When tonic stimulation of multiple locations is provided by apparatus10, implantable device 200 can deliver evenly distributed pulses withinthe stimulation interval.

When tonic sequence stimulation is provided by apparatus 10, implantabledevice 200 can deliver a sequence of monophasic pulses, such as onepulse for each of multiple locations (e.g. 2, 3, 4, 5, and/or morediscrete tissue volume locations stimulated sequentially, and in arepeated arrangement). For tonic sequence stimulation of multiplelocations, implantable device 200 can sequence the pulses within thestimulation interval per the pulse width and inter-pulse gaps for eachlocation (e.g. the sequence of pulses is produced based on or otherwiseto accommodate the pulse width and inter-pulse gaps intended for eachlocation to be stimulated, such as to avoid overlapping of pulses).

In some embodiments, apparatus 10 includes available programs (e.g.created by apparatus 10 and/or a clinician user of apparatus 10) forstimulating different anatomical locations (e.g. back, leg, and thelike, and/or multiple locations within the back, leg, and the like). Insome embodiments, apparatus 10 is configured to operate in an “adjacentmode”, in which apparatus 10 delivers a stimulation pulse in a firstlocation, then a second location, and so on, and repeats. Individualcycles of stimulating a sequence of different locations can be separatedby a delay. Alternatively or additionally, apparatus 10 can beconfigured to operate in an “evenly spaced mode”—where pulses are evenlyspaced over a time period.

Referring now to FIGS. 28A-G, in some embodiments apparatus 10 andimplantable device 200 are configured to perform charge recovery withintissue in a passive arrangement. The charge recovery is performed tomaintain a charge balance in the tissue. Implantable device 200 of FIG.28A can comprise a current source CS₁, a switch S₁, a DC blockingcapacitor C_(DCB), and two stimulation elements 260 a and 260 b, eachconnected as shown. Current source CS₁ is attached to a power supply 270that provides voltage V_(DD), also as shown. The tissue receivingstimulation energy from stimulation elements 260 a and 260 b (e.g.electrodes), tissue T₁, can be electrically modeled as a resistor R₂that is in series with a parallel connection of a capacitor C₁ and aresistor R₁, as shown.

In FIG. 28B, implantable device 200 is configured in a stimulation phasewith current source CS₁ providing current, switch S₁ open, and currentflowing in the direction shown, through capacitor C_(DCB) and tissue T₁(e.g. a volume of tissue). During this stimulation phase, chargeaccumulates in tissue T₁. In FIG. 28C, implantable device 200 is in apassive charge recovery phase with current source CS₁ not providingcurrent, and switch S₁ closed. During this charge recovery phase of FIG.28C, stimulation elements 260 a and 260 b are shorted together, throughcapacitor C_(DCB), and current flows in the direction shown, throughswitch S₁, removing the charge in tissue T₁ developed during thestimulation phase of FIG. 28B.

In FIG. 28D, a plot of current versus time is shown for the stimulationand passive charge recovery arrangement of FIGS. 28B-C. A series ofstimulation pulses are delivered, each with a time period TP₁. In thetime between stimulation pulses, time period TP₂, charge recovery occursfor a time period TP₃ that is based on a RC discharge curve, where anassociated resistance R_(TOT) and capacitance C_(TOT) represents thetotal resistance and capacitance, respectively, in the discharge path.Time period TP₃ is typically on the order of a few milliseconds.

The passive charge recovery described in reference to FIGS. 28C-Dprovides energy efficiency since energy (current) is only applied byimplantable device 200 (e.g. by energy storage assembly 270, typically abattery or capacitor) during the stimulation phase (e.g. versus activecharge recovery in which energy is provided in both stimulation phasesand charge recovery phases). In the embodiment shown in FIG. 28D, thestimulation rate is sufficiently low (e.g. less than 1 kHz) that thecharge recovery period TP₃ is less than the time between stimulationpulses, time period TP₂. However in some embodiments, the stimulationrate is sufficiently high such that the charge recovery period TP₃ isgreater than the time between pulses, time period TP₂, such as is shownin FIG. 28E.

In these high stimulation rate embodiments (e.g. at least 1 kHz up tohundreds of KHz), the duration of the stimulation pulse TP₁ and timebetween pulses TP₂ is much shorter than the RC time constant representedby time period TP₃, such as when each is on the order of one-tenth toone-five hundredth the duration of TP₃. In these embodiments,implantable device 200 is configured to allow charge due build up on theDC blocking capacitor C_(DCB). This built-up charge translates to a biasvoltage across capacitor C_(DCB), which causes current to flow duringthe charge recovery period. An equilibrium is reached when the biasvoltage across capacitor C_(DCB) equals the total resistance in thestimulation (R_(TOT)) path times the stimulation current when timeperiod TP₁ and TP₂ are equal.

FIGS. 28F and 28G show waveforms of current through stimulation elements260 a and 260 b (e.g. the current through tissue T₁) and voltagedeveloped across capacitor C_(DCB) at low and high stimulation rates,respectively. As shown in FIG. 28G, a bias voltage is developed acrosscapacitor C_(DCB), which is approximately equal to the stimulationcurrent during the stimulation phase times R_(TOT) (the total seriesresistance in the stimulation path). An increased compliance voltage isrequired by current source CS₁ to overcome the bias voltage of capacitorC_(DCB). In some embodiments, there is a fixed minimum compliancevoltage (minimum setting for the power supply 270 that powers thecurrent source CS₁) and the stimulation current amplitude times R_(TOT)is less than or equal to 50% of the minimum compliance voltage. In theseembodiments, energy can be recovered that would otherwise be wasted dueto the minimum compliance voltage being greater than that required foractive recovery. The long RC time constant requires a minimum amount oftime (e.g. at least 2 milliseconds) for equilibrium to be reached. Theasymmetry in the waveform can be mitigated by implantable device 200ramping up and ramping down the stimulation current amplitude at thestart and end of a time period in which stimulation energy is delivered.

The equilibrium bias voltage on capacitor C_(DCB) is proportional to theratio of the stimulation period TP₁ and the recovery time TP₂, such thatincreasing the recovery time TP₂ relative to the stimulation time TP₁will proportionally reduce the bias voltage on capacitor C_(DCB), whichwill reduce the required compliance voltage. In this arrangement,control is provided in shaping the charge recovery phase, as both therecovery time and the stimulation path resistance can be manipulated tochange the characteristics of the recovery pulse. For example,implantable device 200 can be configured to manipulate the timing inwhich switch S1 is opened and/or closed, to control timing and/orduration of charge recovery. Alternatively or additionally, implantabledevice 200 can be configured to manipulate the impedance of thedischarge path, such as when implantable device 200 includes one or moreresistive components that can be included and/or excluded from thestimulation path.

While the embodiment of FIGS. 28A-G is shown with two electrodes asstimulation elements 260, four, six, eight, or more stimulation elements260 (e.g. electrodes) can be similarly configured to perform the passivecharge recovery.

While the preferred embodiments of the devices and methods have beendescribed in reference to the environment in which they were developed,they are merely illustrative of the principles of the present inventiveconcepts. Modification or combinations of the above-describedassemblies, other embodiments, configurations, and methods for carryingout the invention, and variations of aspects of the invention that areobvious to those of skill in the art are intended to be within the scopeof the claims. In addition, where this application has listed the stepsof a method or procedure in a specific order, it may be possible, oreven expedient in certain circumstances, to change the order in whichsome steps are performed, and it is intended that the particular stepsof the method or procedure claim set forth herebelow not be construed asbeing order-specific unless such order specificity is expressly statedin the claim.

1.-47. (canceled)
 48. A medical apparatus for a patient, comprising: animplantable system including a first implantable device comprising: afirst lead comprising a first set of multiple stimulation elementscomprising at least a first stimulation element and a second stimulationelement, wherein the first set of multiple stimulation elements areconfigured to deliver stimulation energy to the patient; and animplantable controller comprising a current source, wherein thecontroller is configured to: configure the first stimulation elementelements as a cathode, and configure the second stimulation element andeach of any additional stimulation elements as an anode; wherein thecurrent source is configured to deliver a first current pulse to thefirst stimulation element, wherein the first current pulse passesthrough tissue and is received by the second stimulation element andeach of the any additional stimulation elements; wherein the controlleris further configured to measure a first voltage pulse that results atthe first stimulation element due to the delivery of the first currentpulse; and wherein the controller is further configured to determine theapproximate impedance of the first stimulation element based on theresulting first voltage pulse.
 49. The apparatus according to claim 48,wherein the approximate impedance of the first stimulation element is anupper bound of the actual impedance of the first stimulation element.50. The apparatus according to claim 48, wherein the controller isfurther configured to: configure the second stimulation element as acathode, and configure the first stimulation element and each of the anyadditional stimulation elements as an anode, wherein the current sourceis further configured to deliver a second current pulse to the secondstimulation element, wherein the second current pulse passes throughtissue and is received by the first stimulation element and each of theany additional stimulation elements; wherein the controller is furtherconfigured to measure a second voltage pulse that results at the secondstimulation element due to the delivery of the second current pulse; andwherein the controller is further configured to determine theapproximate impedance of the second stimulation element based on theresulting second voltage pulse.
 51. The apparatus according to claim 48,wherein the first implantable device further comprises: a second leadcomprising a second set of multiple stimulation elements comprising atleast a third stimulation element and a set of one or more additionalsecond lead stimulation elements, wherein the second set of multiplestimulation elements are configured to deliver stimulation energy to thepatient, wherein the controller is further configured to: configure thethird stimulation element of the second set of multiple stimulationelements as a cathode, and configure each of the stimulation elements ofthe set of one or more additional second lead stimulation elements as ananode, wherein the current source is further configured to deliver asecond current pulse to the third stimulation element, wherein thesecond current pulse passes through tissue and is received by each ofthe stimulation elements of the set of one or more additional secondlead stimulation elements; wherein the controller is further configuredto measure a second voltage pulse that results at the third stimulationelement due to the delivery of the second current pulse; and wherein thecontroller is further configured to determine the approximate impedanceof the third stimulation element based on the resulting second voltagepulse.
 52. The apparatus according to claim 48, wherein the controlleris configured to determine whether a short circuit is present betweenany two or more of the first set of multiple stimulation elements. 53.The apparatus according to claim 52, wherein the controller determines ashort circuit is present when the first voltage pulse is at or below athreshold value.
 54. The apparatus according to claim 53, wherein thethreshold value is approximately zero volts.
 55. The apparatus accordingto claim 53, wherein the controller is further configured to determinewhich of the stimulation elements form the short circuit.
 56. Theapparatus according to claim 52, wherein the first implantable devicefurther comprises a multiplexor configured to electrically attach any ofthe stimulation elements to ground, and to subsequently determine if theshort circuit is present.
 57. The apparatus according to claim 56,wherein the current source is configured to deliver a current to thefirst stimulation element and wherein the controller is configured todetect the short circuit by measuring the voltage at the secondstimulation element and each of the any additional stimulation elements.58. The apparatus according to claim 57, wherein the short circuit isdetected if a measured voltage is above a threshold value.
 59. Theapparatus according to claim 48, wherein the controller is configured todetermine whether an open circuit is present at the first stimulationelement.
 60. The apparatus according to claim 59, wherein the currentsource is configured to deliver a current to the first stimulationelement; wherein the controller is configured to detect the open circuitby measuring the voltage at the first stimulation element; and whereinthe open circuit is detected if the measured voltage is above athreshold value.
 61. The apparatus according to claim 48, furthercomprising: an external system configured to transmit one or moretransmission signals to the implantable system, each transmission signalcomprising at least power or data, wherein the external systemcomprises: a first external device comprising: at least one externalantenna configured to transmit a first transmission signal to theimplantable system, the first transmission signal comprising at leastpower or data; an external transmitter configured to drive the at leastone external antenna; an external power supply configured to providepower to at least the external transmitter; and an external controllerconfigured to control the external transmitter.
 62. The apparatusaccording to claim 61, wherein the first implantable device furthercomprises: at least one implantable antenna configured to receive thefirst transmission signal from the first external device; an implantablereceiver configured to receive the first transmission signal from the atleast one implantable antenna; an implantable controller configured tocontrol the stimulation energy delivered by the first set of multiplestimulation elements; an implantable energy storage assembly configuredto provide power to an element selected from the group consisting of:the first set of stimulation elements, the implantable controller, theimplantable receiver, and combinations thereof; and an implantablehousing surrounding at least the implantable controller and theimplantable receiver.